BASELINE: Update Chromium to 88.0.4324.208

Change-Id: I3ae87d23e4eff4b4a469685658740a213600c667
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

55 files changed, 1469 insertions, 122 deletions

diff --git a/chromium/components/feed/core/common/pref_names.cc b/chromium/components/feed/core/common/pref_names.cc
index a50a96ff852..70cd1594940 100644
--- a/chromium/components/feed/core/common/pref_names.cc
+++ b/chromium/components/feed/core/common/pref_names.cc
@@ -36,6 +36,9 @@ const char kHostOverrideBlessNonce[] = "feed.host_override.bless_nonce";
 const char kHasReachedClickAndViewActionsUploadConditions[] =
     "feed.clicks_and_views_upload_conditions_reached";
 const char kLastFetchHadNoticeCard[] = "feed.last_fetch_had_notice_card";
+const char kLastRefreshWasSignedIn[] = "feed.last_refresh_was_signed_in";
+const char kNoticeCardViewsCount[] = "feed.notice_card_views_count";
+const char kNoticeCardClicksCount[] = "feed.notice_card_clicks_count";
 
 const char kThrottlerRequestCountListPrefName[] =
     "feedv2.request_throttler.request_counts";
@@ -68,6 +71,9 @@ void RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(
       feed::prefs::kHasReachedClickAndViewActionsUploadConditions, false);
   registry->RegisterBooleanPref(feed::prefs::kLastFetchHadNoticeCard, true);
+  registry->RegisterBooleanPref(feed::prefs::kLastRefreshWasSignedIn, false);
+  registry->RegisterIntegerPref(feed::prefs::kNoticeCardViewsCount, 0);
+  registry->RegisterIntegerPref(feed::prefs::kNoticeCardClicksCount, 0);
   UserClassifier::RegisterProfilePrefs(registry);
 }
 
diff --git a/chromium/components/feed/core/common/pref_names.h b/chromium/components/feed/core/common/pref_names.h
index 9c381483e65..93116f51d2e 100644
--- a/chromium/components/feed/core/common/pref_names.h
+++ b/chromium/components/feed/core/common/pref_names.h
@@ -46,16 +46,26 @@ extern const char kHostOverrideBlessNonce[];
 // to enable the upload of click and view actions in the feed with the notice
 // card when using the feature kInterestFeedConditionalClickAndViewActionUpload.
 // This is for when the privacy notice card is at the second position in the
-// feed. Currently only used in V1.
+// feed.
 extern const char kHasReachedClickAndViewActionsUploadConditions[];
 
 // The pref name for the bit that determines whether the notice card was present
 // in the feed in the last fetch of content. The notice card is considered as
 // present by default to make sure that the upload of click and view actions
 // doesn't take place when the notice card is present but has not yet been
-// detected. Currently only used in V1.
+// detected.
 extern const char kLastFetchHadNoticeCard[];
 
+// The pref name for the bit that determines whether the last refresh request
+// was signed in. Currently only used in V1.
+extern const char kLastRefreshWasSignedIn[];
+
+// The pref name for the counter for the number of views on the notice card.
+extern const char kNoticeCardViewsCount[];
+
+// The pref name for the counter for the number of clicks on the notice card.
+extern const char kNoticeCardClicksCount[];
+
 // The following prefs are used only by v2.
 
 // The pref name for the request throttler counts.
diff --git a/chromium/components/feed/core/feed_networking_host.cc b/chromium/components/feed/core/feed_networking_host.cc
index e6ab4ac9321..b6104f523d7 100644
--- a/chromium/components/feed/core/feed_networking_host.cc
+++ b/chromium/components/feed/core/feed_networking_host.cc
@@ -345,7 +345,8 @@ void NetworkFetch::OnSimpleLoaderComplete(
                             static_cast<int>(response_body.size() / 1024));
   }
 
-  std::move(done_callback_).Run(status_code, std::move(response_body));
+  std::move(done_callback_)
+      .Run(status_code, std::move(response_body), !access_token_.empty());
 }
 
 FeedNetworkingHost::FeedNetworkingHost(
@@ -388,12 +389,13 @@ void FeedNetworkingHost::NetworkFetchFinished(
     NetworkFetch* fetch,
     ResponseCallback callback,
     int32_t http_code,
-    std::vector<uint8_t> response_body) {
+    std::vector<uint8_t> response_body,
+    bool is_signed_in) {
   auto fetch_iterator = pending_requests_.find(fetch);
   CHECK(fetch_iterator != pending_requests_.end());
   pending_requests_.erase(fetch_iterator);
 
-  std::move(callback).Run(http_code, std::move(response_body));
+  std::move(callback).Run(http_code, std::move(response_body), is_signed_in);
 }
 
 }  // namespace feed
diff --git a/chromium/components/feed/core/feed_networking_host.h b/chromium/components/feed/core/feed_networking_host.h
index f20873554e7..dcfec632efd 100644
--- a/chromium/components/feed/core/feed_networking_host.h
+++ b/chromium/components/feed/core/feed_networking_host.h
@@ -45,7 +45,8 @@ class FeedNetworkingHost {
   // status code(if the request succeeded in reaching the server).
   using ResponseCallback =
       base::OnceCallback<void(int32_t status_code,
-                              std::vector<uint8_t> response_bytes)>;
+                              std::vector<uint8_t> response_bytes,
+                              bool is_signed_in)>;
 
   FeedNetworkingHost(
       signin::IdentityManager* identity_manager,
@@ -74,7 +75,8 @@ class FeedNetworkingHost {
   void NetworkFetchFinished(NetworkFetch* fetch,
                             ResponseCallback callback,
                             int32_t http_code,
-                            std::vector<uint8_t> response_body);
+                            std::vector<uint8_t> response_body,
+                            bool isSignedIn);
 
   base::flat_set<std::unique_ptr<NetworkFetch>, base::UniquePtrComparator>
       pending_requests_;
diff --git a/chromium/components/feed/core/feed_networking_host_unittest.cc b/chromium/components/feed/core/feed_networking_host_unittest.cc
index 9361ec2dd7d..da5af8defdc 100644
--- a/chromium/components/feed/core/feed_networking_host_unittest.cc
+++ b/chromium/components/feed/core/feed_networking_host_unittest.cc
@@ -9,7 +9,7 @@
 #include "base/bind.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/simple_test_tick_clock.h"
@@ -46,16 +46,20 @@ class MockResponseDoneCallback {
  public:
   MockResponseDoneCallback() : has_run(false), code(0) {}
 
-  void Done(int32_t http_code, std::vector<uint8_t> response) {
+  void Done(int32_t http_code,
+            std::vector<uint8_t> response,
+            bool is_signed_in) {
     EXPECT_FALSE(has_run);
     has_run = true;
     code = http_code;
     response_bytes = std::move(response);
+    is_signed_in_result = is_signed_in;
   }
 
   bool has_run;
   int32_t code;
   std::vector<uint8_t> response_bytes;
+  bool is_signed_in_result;
 };
 
 }  // namespace
@@ -266,6 +270,15 @@ TEST_F(FeedNetworkingHostTest, ShouldSetHeadersCorrectly) {
   EXPECT_EQ(authorization, "Bearer access_token");
 }
 
+TEST_F(FeedNetworkingHostTest, ProvideIsSignedInBitInResult) {
+  MockResponseDoneCallback done_callback;
+  SendRequestAndRespond("http://foobar.com/feed", "POST", "body", "",
+                        net::HTTP_OK, network::URLLoaderCompletionStatus(),
+                        &done_callback);
+
+  EXPECT_TRUE(done_callback.is_signed_in_result);
+}
+
 TEST_F(FeedNetworkingHostTest, ShouldNotSendContentEncodingForEmptyBody) {
   MockResponseDoneCallback done_callback;
   net::HttpRequestHeaders headers;
diff --git a/chromium/components/feed/core/proto/BUILD.gn b/chromium/components/feed/core/proto/BUILD.gn
index 2ff52bed0fc..9244b9aebc5 100644
--- a/chromium/components/feed/core/proto/BUILD.gn
+++ b/chromium/components/feed/core/proto/BUILD.gn
@@ -28,7 +28,9 @@ proto_library("proto_v2") {
     "v2/ui.proto",
     "v2/wire/action_payload.proto",
     "v2/wire/capability.proto",
+    "v2/wire/chrome_client_info.proto",
     "v2/wire/chrome_feed_response_metadata.proto",
+    "v2/wire/chrome_fulfillment_info.proto",
     "v2/wire/client_info.proto",
     "v2/wire/consistency_token.proto",
     "v2/wire/content_id.proto",
@@ -92,6 +94,7 @@ if (is_android) {
       "wire/action_request.proto",
       "wire/action_type.proto",
       "wire/capability.proto",
+      "wire/chrome_fulfillment_info.proto",
       "wire/client_info.proto",
       "wire/consistency_token.proto",
       "wire/content_id.proto",
diff --git a/chromium/components/feed/core/proto/v2/store.proto b/chromium/components/feed/core/proto/v2/store.proto
index 29ba828c4ea..206d90596db 100644
--- a/chromium/components/feed/core/proto/v2/store.proto
+++ b/chromium/components/feed/core/proto/v2/store.proto
@@ -51,15 +51,24 @@ message StreamData {
   bool logging_enabled = 8;
   // Has the privacy notice been fulfilled?
   bool privacy_notice_fulfilled = 9;
+
   reserved 3, 5;
 }
 
 // Data that doesn't belong to a stream.
 message Metadata {
+  // Session identifier used for signed-out feed requests and interactions.
+  message SessionID {
+    string token = 1;
+    int64 expiry_time_ms = 2;
+  }
+
   // Token used to read or write to the same storage.
   bytes consistency_token = 1;
   // ID for the next pending action.
   int32 next_action_id = 2;
+  // The most recent session identifier.
+  SessionID session_id = 3;
 }
 
 // A set of StreamStructures that should be applied to a stream.
diff --git a/chromium/components/feed/core/proto/v2/wire/chrome_client_info.proto b/chromium/components/feed/core/proto/v2/wire/chrome_client_info.proto
new file mode 100644
index 00000000000..26f71a2b690
--- /dev/null
+++ b/chromium/components/feed/core/proto/v2/wire/chrome_client_info.proto
@@ -0,0 +1,17 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+syntax = "proto2";
+
+package feedwire;
+
+option optimize_for = LITE_RUNTIME;
+
+// Information about the client performing the request, relevant only to Chrome
+// surfaces.
+message ChromeClientInfo {
+  // The signed-out session identifier (Zwieback) token, for clients which embed
+  // this information in-band instead of using an HTTP Cookie.
+  optional string session_id = 3;
+}
diff --git a/chromium/components/feed/core/proto/v2/wire/chrome_feed_response_metadata.proto b/chromium/components/feed/core/proto/v2/wire/chrome_feed_response_metadata.proto
index c6ec3fcdbe7..2eb9cad7263 100644
--- a/chromium/components/feed/core/proto/v2/wire/chrome_feed_response_metadata.proto
+++ b/chromium/components/feed/core/proto/v2/wire/chrome_feed_response_metadata.proto
@@ -11,4 +11,5 @@ option optimize_for = LITE_RUNTIME;
 message ChromeFeedResponseMetadata {
   optional bool privacy_notice_fulfilled = 1;
   optional bool logging_enabled = 2;
+  optional string session_id = 3;
 }
diff --git a/chromium/components/feed/core/proto/v2/wire/chrome_fulfillment_info.proto b/chromium/components/feed/core/proto/v2/wire/chrome_fulfillment_info.proto
new file mode 100644
index 00000000000..22ea6991dcb
--- /dev/null
+++ b/chromium/components/feed/core/proto/v2/wire/chrome_fulfillment_info.proto
@@ -0,0 +1,17 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+syntax = "proto2";
+
+package feedwire;
+
+option optimize_for = LITE_RUNTIME;
+
+// Information on how to do content fulfillment for Chrome.
+message ChromeFulfillmentInfo {
+  // Whether the notice card has already been acknowledged by the user based on
+  // their views and clicks on the card. This is different from when the user
+  // explicitly dismiss the notice card by touching the button.
+  optional bool notice_card_acknowledged = 1;
+}
diff --git a/chromium/components/feed/core/proto/v2/wire/client_info.proto b/chromium/components/feed/core/proto/v2/wire/client_info.proto
index 40eaca72c48..a54ae75ec48 100644
--- a/chromium/components/feed/core/proto/v2/wire/client_info.proto
+++ b/chromium/components/feed/core/proto/v2/wire/client_info.proto
@@ -8,6 +8,7 @@ package feedwire;
 
 option optimize_for = LITE_RUNTIME;
 
+import "components/feed/core/proto/v2/wire/chrome_client_info.proto";
 import "components/feed/core/proto/v2/wire/display_info.proto";
 import "components/feed/core/proto/v2/wire/version.proto";
 
@@ -58,4 +59,8 @@ message ClientInfo {
   // this comes from GServices check-in which uses the SIM card MCC (mobile
   // country code), with fallback to IP geo lookup.
   optional string device_country = 9;
+
+  // Information about the client performing the request, relevant only to
+  // Chrome surfaces.
+  optional ChromeClientInfo chrome_client_info = 338478298;
 }
diff --git a/chromium/components/feed/core/proto/v2/wire/feed_query.proto b/chromium/components/feed/core/proto/v2/wire/feed_query.proto
index e69e919fae6..0cc218f07bb 100644
--- a/chromium/components/feed/core/proto/v2/wire/feed_query.proto
+++ b/chromium/components/feed/core/proto/v2/wire/feed_query.proto
@@ -8,6 +8,7 @@ package feedwire;
 
 option optimize_for = LITE_RUNTIME;
 
+import "components/feed/core/proto/v2/wire/chrome_fulfillment_info.proto";
 import "components/feed/core/proto/v2/wire/token.proto";
 
 message FeedQuery {
@@ -48,5 +49,8 @@ message FeedQuery {
     Tokens in_place_update_tokens = 5;
   }
 
+  // Information on how to do content fulfillment for Chrome.
+  optional ChromeFulfillmentInfo chrome_fulfillment_info = 341477699;
+
   reserved 2;
 }
diff --git a/chromium/components/feed/core/proto/wire/chrome_fulfillment_info.proto b/chromium/components/feed/core/proto/wire/chrome_fulfillment_info.proto
new file mode 100644
index 00000000000..e78acbaedcb
--- /dev/null
+++ b/chromium/components/feed/core/proto/wire/chrome_fulfillment_info.proto
@@ -0,0 +1,20 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+syntax = "proto2";
+
+package feedwire1;
+
+option optimize_for = LITE_RUNTIME;
+
+option java_package = "org.chromium.components.feed.core.proto.wire";
+option java_outer_classname = "ChromeFulfillmentInfoProto";
+
+// Information on how to do content fulfillment for Chrome.
+message ChromeFulfillmentInfo {
+  // Whether the notice card has already been acknowledged by the user based on
+  // their views and clicks on the card. This is different from when the user
+  // explicitly dismiss the notice card by touching the button.
+  optional bool notice_card_acknowledged = 1;
+}
diff --git a/chromium/components/feed/core/proto/wire/feed_query.proto b/chromium/components/feed/core/proto/wire/feed_query.proto
index 2620819c328..e105058af93 100644
--- a/chromium/components/feed/core/proto/wire/feed_query.proto
+++ b/chromium/components/feed/core/proto/wire/feed_query.proto
@@ -11,6 +11,8 @@ option optimize_for = LITE_RUNTIME;
 option java_package = "org.chromium.components.feed.core.proto.wire";
 option java_outer_classname = "FeedQueryProto";
 
+import "components/feed/core/proto/wire/chrome_fulfillment_info.proto";
+
 message FeedQuery {
   enum RequestReason {
     // Bucket for any not listed. Should not be used (prefer adding a new
@@ -49,4 +51,7 @@ message FeedQuery {
   // Used to fetch the next page when scrolling copied from
   // Token.next_page_token
   optional bytes page_token = 2;
+
+  // Information on how to do content fulfillment for Chrome.
+  optional ChromeFulfillmentInfo chrome_fulfillment_info = 3;
 }
diff --git a/chromium/components/feed/core/v2/BUILD.gn b/chromium/components/feed/core/v2/BUILD.gn
index 3de0962ba05..6331e2eceda 100644
--- a/chromium/components/feed/core/v2/BUILD.gn
+++ b/chromium/components/feed/core/v2/BUILD.gn
@@ -27,6 +27,8 @@ source_set("feed_core_v2") {
     "image_fetcher.h",
     "metrics_reporter.cc",
     "metrics_reporter.h",
+    "notice_card_tracker.cc",
+    "notice_card_tracker.h",
     "offline_page_spy.cc",
     "offline_page_spy.h",
     "prefs.cc",
@@ -63,6 +65,8 @@ source_set("feed_core_v2") {
     "tasks/load_stream_from_store_task.h",
     "tasks/load_stream_task.cc",
     "tasks/load_stream_task.h",
+    "tasks/prefetch_images_task.cc",
+    "tasks/prefetch_images_task.h",
     "tasks/upload_actions_task.cc",
     "tasks/upload_actions_task.h",
     "tasks/wait_for_store_initialize_task.cc",
@@ -71,6 +75,7 @@ source_set("feed_core_v2") {
     "types.h",
   ]
   deps = [
+    ":common",
     "//components/feed/core:feed_core",
     "//components/feed/core/common:feed_core_common",
     "//components/history/core/browser",
@@ -97,6 +102,11 @@ source_set("feed_core_v2") {
   ]
 }
 
+source_set("common") {
+  sources = [ "common_enums.h" ]
+  deps = []
+}
+
 source_set("core_unit_tests") {
   testonly = true
   sources = [
@@ -106,6 +116,7 @@ source_set("core_unit_tests") {
     "feed_stream_unittest.cc",
     "image_fetcher_unittest.cc",
     "metrics_reporter_unittest.cc",
+    "notice_card_tracker_unittest.cc",
     "proto_util_unittest.cc",
     "protocol_translator_unittest.cc",
     "public/feed_service_unittest.cc",
@@ -122,6 +133,7 @@ source_set("core_unit_tests") {
   ]
 
   deps = [
+    ":common",
     ":feed_core_v2",
     ":unit_tests_bundle_data",
     "//base",
diff --git a/chromium/components/feed/core/v2/common_enums.h b/chromium/components/feed/core/v2/common_enums.h
new file mode 100644
index 00000000000..070dfc83916
--- /dev/null
+++ b/chromium/components/feed/core/v2/common_enums.h
@@ -0,0 +1,86 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_FEED_CORE_V2_COMMON_ENUMS_H_
+#define COMPONENTS_FEED_CORE_V2_COMMON_ENUMS_H_
+
+// Unlike most code from feed/core, these enums are used by both iOS and
+// Android.
+namespace feed {
+
+// Values for the UMA ContentSuggestions.Feed.EngagementType
+// histogram. These values are persisted to logs. Entries should not be
+// renumbered and numeric values should never be reused. This must be kept
+// in sync with FeedEngagementType in enums.xml.
+enum class FeedEngagementType {
+  kFeedEngaged = 0,
+  kFeedEngagedSimple = 1,
+  kFeedInteracted = 2,
+  kDeprecatedFeedScrolled = 3,
+  kFeedScrolled = 4,
+  kMaxValue = kFeedScrolled,
+};
+
+// Values for the UMA ContentSuggestions.Feed.UserActions
+// histogram. These values are persisted to logs. Entries should not be
+// renumbered and numeric values should never be reused. This must be kept
+// in sync with FeedUserActionType in enums.xml.
+// Note: Most of these have a corresponding UserMetricsAction reported here.
+// Exceptions are described below.
+enum class FeedUserActionType {
+  // User tapped on card, opening the article in the same tab.
+  kTappedOnCard = 0,
+  // This is not an actual user action, so there will be no UserMetricsAction
+  // reported for this.
+  kShownCard = 1,
+  // User tapped on 'Send Feedback' in the back of card menu.
+  kTappedSendFeedback = 2,
+  // Discover feed header menu 'Learn More' tapped.
+  kTappedLearnMore = 3,
+  // User Tapped Hide Story in the back of card menu.
+  kTappedHideStory = 4,
+  // User Tapped  Not Interested In X in the back of card menu.
+  kTappedNotInterestedIn = 5,
+  // Discover feed header menu 'Manage Interests' tapped.
+  kTappedManageInterests = 6,
+  kTappedDownload = 7,
+  // User opened the article in a new tab from the back of card menu.
+  kTappedOpenInNewTab = 8,
+  // User opened the back of card menu.
+  kOpenedContextMenu = 9,
+  // User action not reported here. See Suggestions.SurfaceVisible.
+  kOpenedFeedSurface = 10,
+  // User opened the article in an incognito tab from the back of card menu.
+  kTappedOpenInNewIncognitoTab = 11,
+  // Ephemeral change, likely due to hide story or not interested in.
+  kEphemeralChange = 12,
+  // Ephemeral change undone, likely due to pressing 'undo' on the snackbar.
+  kEphemeralChangeRejected = 13,
+  // Discover feed visibility toggled from header menu.
+  kTappedTurnOn = 14,
+  kTappedTurnOff = 15,
+  // Discover feed header menu 'Manage Activity' tapped.
+  kTappedManageActivity = 16,
+  // User added article to 'Read Later' list.
+  kAddedToReadLater = 17,
+  // User closed the back of card menu.
+  kClosedContextMenu = 18,
+  // Ephemeral change committed, likely due to dismissing an 'undo' snackbar.
+  kEphemeralChangeCommited = 19,
+  // User opened a Dialog. e.g. Report content Dialog. User action not reported
+  // here.
+  kOpenedDialog = 20,
+  // User closed a Dialog. e.g. Report content Dialog.
+  kClosedDialog = 21,
+  // User action caused a snackbar to be shown. User action not reported here.
+  kShowSnackbar = 22,
+  // User opened the native back of card menu.
+  kOpenedNativeContextMenu = 23,
+  // Highest enumerator. Recommended by Histogram metrics best practices.
+  kMaxValue = kOpenedNativeContextMenu,
+};
+
+}  // namespace feed
+
+#endif  // COMPONENTS_FEED_CORE_V2_COMMON_ENUMS_H_
diff --git a/chromium/components/feed/core/v2/config.cc b/chromium/components/feed/core/v2/config.cc
index 753f275f00b..309e4583b89 100644
--- a/chromium/components/feed/core/v2/config.cc
+++ b/chromium/components/feed/core/v2/config.cc
@@ -76,6 +76,21 @@ void OverrideWithFinch(Config* config) {
           kInterestFeedV2, "upload_actions_on_enter_background",
           config->upload_actions_on_enter_background);
 
+  config->send_signed_out_session_logs =
+      base::GetFieldTrialParamByFeatureAsBool(
+          kInterestFeedV2, "send_signed_out_session_logs",
+          config->send_signed_out_session_logs);
+
+  config->session_id_max_age =
+      base::TimeDelta::FromDays(base::GetFieldTrialParamByFeatureAsInt(
+          kInterestFeedV2, "session_id_max_age_days",
+          config->session_id_max_age.InDays()));
+
+  config->max_prefetch_image_requests_per_refresh =
+      base::GetFieldTrialParamByFeatureAsInt(
+          kInterestFeedV2, "max_prefetch_image_requests_per_refresh",
+          config->max_prefetch_image_requests_per_refresh);
+
   // Erase any capabilities with "enable_CAPABILITY = false" set.
   base::EraseIf(config->experimental_capabilities, CapabilityDisabled);
 }
diff --git a/chromium/components/feed/core/v2/config.h b/chromium/components/feed/core/v2/config.h
index 2789d0cd219..1eb0d612c12 100644
--- a/chromium/components/feed/core/v2/config.h
+++ b/chromium/components/feed/core/v2/config.h
@@ -38,6 +38,12 @@ struct Config {
   int load_more_trigger_lookahead = 5;
   // Whether to attempt uploading actions when Chrome is hidden.
   bool upload_actions_on_enter_background = true;
+  // Whether to send (pseudonymous) logs for signed-out sessions.
+  bool send_signed_out_session_logs = false;
+  // The max age of a signed-out session token.
+  base::TimeDelta session_id_max_age = base::TimeDelta::FromDays(30);
+  // Maximum number of images prefetched per refresh.
+  int max_prefetch_image_requests_per_refresh = 50;
   // Set of optional capabilities included in requests. See
   // CreateFeedQueryRequest() for required capabilities.
   base::flat_set<feedwire::Capability> experimental_capabilities = {
diff --git a/chromium/components/feed/core/v2/feed_network.h b/chromium/components/feed/core/v2/feed_network.h
index b0836218f4f..a5676de45a4 100644
--- a/chromium/components/feed/core/v2/feed_network.h
+++ b/chromium/components/feed/core/v2/feed_network.h
@@ -30,6 +30,8 @@ class FeedNetwork {
     NetworkResponseInfo response_info;
     // Response body if one was received.
     std::unique_ptr<feedwire::Response> response_body;
+    // Whether the request was signed in.
+    bool was_signed_in;
   };
 
   // Result of SendActionRequest.
diff --git a/chromium/components/feed/core/v2/feed_network_impl.cc b/chromium/components/feed/core/v2/feed_network_impl.cc
index 4cc86a94c45..5f2c68ad471 100644
--- a/chromium/components/feed/core/v2/feed_network_impl.cc
+++ b/chromium/components/feed/core/v2/feed_network_impl.cc
@@ -12,6 +12,7 @@
 #include "base/containers/flat_set.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/strings/strcat.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
 #include "components/feed/core/common/pref_names.h"
@@ -39,6 +40,9 @@
 #include "third_party/protobuf/src/google/protobuf/io/coded_stream.h"
 #include "third_party/zlib/google/compression_utils.h"
 
+// Token override for Feedv2NewTabPageCardInstrumentationTest.java:
+// #define TOKEN_OVERRIDE_FOR_TESTING  "put-test-token-here"
+
 namespace feed {
 namespace {
 constexpr char kApplicationXProtobuf[] = "application/x-protobuf";
@@ -312,8 +316,12 @@ class FeedNetworkImpl::NetworkFetch {
 
     variations::SignedIn signed_in_status = variations::SignedIn::kNo;
     if (!access_token_.empty()) {
+      base::StringPiece token = access_token_;
+#ifdef TOKEN_OVERRIDE_FOR_TESTING
+      token = TOKEN_OVERRIDE_FOR_TESTING;
+#endif
       request.headers.SetHeader(net::HttpRequestHeaders::kAuthorization,
-                                "Bearer " + access_token_);
+                                base::StrCat({"Bearer ", token}));
       signed_in_status = variations::SignedIn::kYes;
     }
 
@@ -329,6 +337,7 @@ class FeedNetworkImpl::NetworkFetch {
         tick_clock_->NowTicks() - entire_send_start_ticks_;
     response_info.fetch_time = base::Time::Now();
     response_info.base_request_url = GetUrlWithoutQuery(url_);
+    response_info.was_signed_in = !access_token_.empty();
 
     // If overriding the feed host, try to grab the Bless nonce. This is
     // strictly informational, and only displayed in snippets-internals.
diff --git a/chromium/components/feed/core/v2/feed_network_impl_unittest.cc b/chromium/components/feed/core/v2/feed_network_impl_unittest.cc
index 6d759773629..c6ad6e97a6e 100644
--- a/chromium/components/feed/core/v2/feed_network_impl_unittest.cc
+++ b/chromium/components/feed/core/v2/feed_network_impl_unittest.cc
@@ -10,7 +10,7 @@
 #include "base/bind.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/test/task_environment.h"
@@ -277,6 +277,7 @@ TEST_F(FeedNetworkTest, SendQueryRequestReceivesResponse) {
       "https://www.google.com/httpservice/retry/TrellisClankService/FeedQuery",
       result.response_info.base_request_url);
   EXPECT_NE(base::Time(), result.response_info.fetch_time);
+  EXPECT_TRUE(result.response_info.was_signed_in);
   EXPECT_EQ(GetTestFeedResponse().response_version(),
             result.response_body->response_version());
 }
diff --git a/chromium/components/feed/core/v2/feed_store.cc b/chromium/components/feed/core/v2/feed_store.cc
index bb0add49a8e..65eafb55d54 100644
--- a/chromium/components/feed/core/v2/feed_store.cc
+++ b/chromium/components/feed/core/v2/feed_store.cc
@@ -7,7 +7,7 @@
 #include <utility>
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/containers/flat_set.h"
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
@@ -501,7 +501,7 @@ void FeedStore::RemoveActions(std::vector<LocalActionId> ids,
   database_->UpdateEntries(
       /*entries_to_save=*/std::make_unique<
           std::vector<std::pair<std::string, feedstore::Record>>>(),
-      /*key_to_remove=*/std::move(keys), std::move(callback));
+      /*keys_to_remove=*/std::move(keys), std::move(callback));
 }
 
 void FeedStore::Write(std::vector<feedstore::Record> records,
diff --git a/chromium/components/feed/core/v2/feed_store_unittest.cc b/chromium/components/feed/core/v2/feed_store_unittest.cc
index db7473c2d58..fe2a1ecd19c 100644
--- a/chromium/components/feed/core/v2/feed_store_unittest.cc
+++ b/chromium/components/feed/core/v2/feed_store_unittest.cc
@@ -11,7 +11,7 @@
 #include "base/strings/strcat.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/task_environment.h"
 #include "components/feed/core/proto/v2/wire/content_id.pb.h"
 #include "components/feed/core/v2/protocol_translator.h"
diff --git a/chromium/components/feed/core/v2/feed_stream.cc b/chromium/components/feed/core/v2/feed_stream.cc
index 022579bcb33..a2794afa866 100644
--- a/chromium/components/feed/core/v2/feed_stream.cc
+++ b/chromium/components/feed/core/v2/feed_stream.cc
@@ -34,6 +34,7 @@
 #include "components/feed/core/v2/tasks/clear_all_task.h"
 #include "components/feed/core/v2/tasks/get_prefetch_suggestions_task.h"
 #include "components/feed/core/v2/tasks/load_stream_task.h"
+#include "components/feed/core/v2/tasks/prefetch_images_task.h"
 #include "components/feed/core/v2/tasks/upload_actions_task.h"
 #include "components/feed/core/v2/tasks/wait_for_store_initialize_task.h"
 #include "components/feed/feed_feature_list.h"
@@ -113,7 +114,7 @@ void FeedStream::Metadata::Populate(feedstore::Metadata metadata) {
   metadata_ = std::move(metadata);
 }
 
-std::string FeedStream::Metadata::GetConsistencyToken() const {
+const std::string& FeedStream::Metadata::GetConsistencyToken() const {
   return metadata_.consistency_token();
 }
 
@@ -122,6 +123,36 @@ void FeedStream::Metadata::SetConsistencyToken(std::string consistency_token) {
   store_->WriteMetadata(metadata_, base::DoNothing());
 }
 
+const std::string& FeedStream::Metadata::GetSessionIdToken() const {
+  return metadata_.session_id().token();
+}
+
+base::Time FeedStream::Metadata::GetSessionIdExpiryTime() const {
+  return base::Time::FromDeltaSinceWindowsEpoch(
+      base::TimeDelta::FromMilliseconds(
+          metadata_.session_id().expiry_time_ms()));
+}
+
+void FeedStream::Metadata::SetSessionId(std::string token,
+                                        base::Time expiry_time) {
+  feedstore::Metadata::SessionID* session_id = metadata_.mutable_session_id();
+  session_id->set_token(std::move(token));
+  session_id->set_expiry_time_ms(
+      expiry_time.ToDeltaSinceWindowsEpoch().InMilliseconds());
+  store_->WriteMetadata(metadata_, base::DoNothing());
+}
+
+void FeedStream::Metadata::MaybeUpdateSessionId(
+    base::Optional<std::string> token,
+    const base::Clock* clock) {
+  if (token && metadata_.session_id().token() != *token) {
+    base::Time expiry_time =
+        token->empty() ? base::Time()
+                       : clock->Now() + GetFeedConfig().session_id_max_age;
+    SetSessionId(*token, expiry_time);
+  }
+}
+
 LocalActionId FeedStream::Metadata::GetNextActionId() {
   uint32_t id = metadata_.next_action_id();
   // Never use 0, as that's an invalid LocalActionId.
@@ -157,7 +188,8 @@ FeedStream::FeedStream(RefreshTaskScheduler* refresh_task_scheduler,
       chrome_info_(chrome_info),
       task_queue_(this),
       request_throttler_(profile_prefs, clock),
-      metadata_(feed_store) {
+      metadata_(feed_store),
+      notice_card_tracker_(profile_prefs) {
   static WireResponseTranslator default_translator;
   wire_response_translator_ = &default_translator;
 
@@ -238,13 +270,32 @@ bool FeedStream::IsActivityLoggingEnabled() const {
 
 void FeedStream::UpdateIsActivityLoggingEnabled() {
   is_activity_logging_enabled_ =
-      model_ && model_->signed_in() && model_->logging_enabled();
+      model_ &&
+      ((model_->signed_in() && model_->logging_enabled()) ||
+       (!model_->signed_in() && GetFeedConfig().send_signed_out_session_logs));
+}
+
+std::string FeedStream::GetSessionId() const {
+  return GetMetadata()->GetSessionIdToken();
+}
+
+void FeedStream::PrefetchImage(const GURL& url) {
+  delegate_->PrefetchImage(url);
 }
 
 void FeedStream::AttachSurface(SurfaceInterface* surface) {
   metrics_reporter_->SurfaceOpened(surface->GetSurfaceId());
+
+  // Skip normal processing when overriding stream data from the internals page.
+  if (forced_stream_update_for_debugging_.updated_slices_size() > 0) {
+    surface_updater_->SurfaceAdded(surface);
+    surface->StreamUpdate(forced_stream_update_for_debugging_);
+    return;
+  }
+
   TriggerStreamLoad();
   surface_updater_->SurfaceAdded(surface);
+
   // Cancel any scheduled model unload task.
   ++unload_on_detach_sequence_number_;
   UpdateCanUploadActionsWithNoticeCard();
@@ -292,7 +343,7 @@ bool FeedStream::IsArticlesListVisible() {
   return profile_prefs_->GetBoolean(prefs::kArticlesListVisible);
 }
 
-std::string FeedStream::GetClientInstanceId() {
+std::string FeedStream::GetClientInstanceId() const {
   return prefs::GetClientInstanceId(*profile_prefs_);
 }
 
@@ -455,6 +506,11 @@ std::string FeedStream::DumpStateForDebugging() {
   return ss.str();
 }
 
+void FeedStream::SetForcedStreamUpdateForDebugging(
+    const feedui::StreamUpdate& stream_update) {
+  forced_stream_update_for_debugging_ = stream_update;
+}
+
 base::Time FeedStream::GetLastFetchTime() {
   const base::Time fetch_time =
       profile_prefs_->GetTime(feed::prefs::kLastFetchAttemptTime);
@@ -556,12 +612,38 @@ bool FeedStream::ShouldForceSignedOutFeedQueryRequest() const {
   return base::TimeTicks::Now() < signed_out_refreshes_until_;
 }
 
-RequestMetadata FeedStream::GetRequestMetadata() {
+RequestMetadata FeedStream::GetRequestMetadata(bool is_for_next_page) const {
   RequestMetadata result;
   result.chrome_info = chrome_info_;
   result.display_metrics = delegate_->GetDisplayMetrics();
   result.language_tag = delegate_->GetLanguageTag();
-  result.client_instance_id = GetClientInstanceId();
+  result.notice_card_acknowledged =
+      notice_card_tracker_.HasAcknowledgedNoticeCard();
+
+  if (is_for_next_page) {
+    // If we are continuing an existing feed, use whatever session continuity
+    // mechanism is currently associated with the stream: client-instance-id
+    // for signed-in feed, session_id token for signed-out.
+    DCHECK(model_);
+    if (model_->signed_in()) {
+      result.client_instance_id = GetClientInstanceId();
+    } else {
+      result.session_id = GetMetadata()->GetSessionIdToken();
+    }
+  } else {
+    // The request is for the first page of the feed. Use client_instance_id
+    // for signed in requests and session_id token (if any, and not expired)
+    // for signed-out.
+    if (delegate_->IsSignedIn() && !ShouldForceSignedOutFeedQueryRequest()) {
+      result.client_instance_id = GetClientInstanceId();
+    } else if (!GetMetadata()->GetSessionIdToken().empty() &&
+               GetMetadata()->GetSessionIdExpiryTime() > clock_->Now()) {
+      result.session_id = GetMetadata()->GetSessionIdToken();
+    }
+  }
+
+  DCHECK(result.session_id.empty() || result.client_instance_id.empty());
+
   return result;
 }
 
@@ -626,6 +708,10 @@ void FeedStream::BackgroundRefreshComplete(LoadStreamTask::Result result) {
   if (result.loaded_new_content_from_network && prefetch_service_)
     prefetch_service_->NewSuggestionsAvailable();
 
+  // Add prefetch images to task queue without waiting to finish
+  // since we treat them as best-effort.
+  task_queue_.AddTask(std::make_unique<PrefetchImagesTask>(this));
+
   refresh_task_scheduler_->RefreshTaskComplete();
 }
 
@@ -693,19 +779,22 @@ void FeedStream::UnloadModel() {
   surface_updater_->SetModel(nullptr);
   model_.reset();
 }
-
 void FeedStream::ReportOpenAction(const std::string& slice_id) {
   int index = surface_updater_->GetSliceIndexFromSliceId(slice_id);
-  if (index >= 0)
-    metrics_reporter_->OpenAction(index);
+  if (index < 0)
+    index = MetricsReporter::kUnknownCardIndex;
+  metrics_reporter_->OpenAction(index);
+  notice_card_tracker_.OnOpenAction(index);
 }
 void FeedStream::ReportOpenVisitComplete(base::TimeDelta visit_time) {
   metrics_reporter_->OpenVisitComplete(visit_time);
 }
 void FeedStream::ReportOpenInNewTabAction(const std::string& slice_id) {
   int index = surface_updater_->GetSliceIndexFromSliceId(slice_id);
-  if (index >= 0)
-    metrics_reporter_->OpenInNewTabAction(index);
+  if (index < 0)
+    index = MetricsReporter::kUnknownCardIndex;
+  metrics_reporter_->OpenInNewTabAction(index);
+  notice_card_tracker_.OnOpenAction(index);
 }
 void FeedStream::ReportOpenInNewIncognitoTabAction() {
   metrics_reporter_->OpenInNewIncognitoTabAction();
@@ -715,9 +804,11 @@ void FeedStream::ReportSliceViewed(SurfaceId surface_id,
   int index = surface_updater_->GetSliceIndexFromSliceId(slice_id);
   if (index >= 0) {
     UpdateShownSlicesUploadCondition(index);
+    notice_card_tracker_.OnSliceViewed(index);
     metrics_reporter_->ContentSliceViewed(surface_id, index);
   }
 }
+// TODO(crbug/1147237): Rename this method and related members?
 bool FeedStream::CanUploadActions() const {
   return can_upload_actions_with_notice_card_ ||
          !prefs::GetLastFetchHadNoticeCard(*profile_prefs_);
@@ -746,11 +837,16 @@ void FeedStream::DeclareHasReachedConditionsToUploadActionsWithNoticeCard() {
 void FeedStream::UpdateShownSlicesUploadCondition(int viewed_slice_index) {
   constexpr int kShownSlicesThreshold = 2;
 
+  DCHECK(model_) << "Model was unloaded while handling a viewed slice";
+
   // Don't take shown slices into consideration when the upload conditions has
   // already been reached.
   if (HasReachedConditionsToUploadActionsWithNoticeCard())
     return;
 
+  if (!model_->signed_in())
+    return;
+
   if (viewed_slice_index + 1 >= kShownSlicesThreshold)
     DeclareHasReachedConditionsToUploadActionsWithNoticeCard();
 }
diff --git a/chromium/components/feed/core/v2/feed_stream.h b/chromium/components/feed/core/v2/feed_stream.h
index 0b3082a4211..7b7fd04e6e7 100644
--- a/chromium/components/feed/core/v2/feed_stream.h
+++ b/chromium/components/feed/core/v2/feed_stream.h
@@ -16,8 +16,10 @@
 #include "base/version.h"
 #include "components/feed/core/common/enums.h"
 #include "components/feed/core/common/user_classifier.h"
+#include "components/feed/core/proto/v2/ui.pb.h"
 #include "components/feed/core/proto/v2/wire/response.pb.h"
 #include "components/feed/core/v2/enums.h"
+#include "components/feed/core/v2/notice_card_tracker.h"
 #include "components/feed/core/v2/protocol_translator.h"
 #include "components/feed/core/v2/public/feed_stream_api.h"
 #include "components/feed/core/v2/request_throttler.h"
@@ -68,6 +70,7 @@ class FeedStream : public FeedStreamApi,
     virtual std::string GetLanguageTag() = 0;
     virtual void ClearAll() = 0;
     virtual bool IsSignedIn() = 0;
+    virtual void PrefetchImage(const GURL& url) = 0;
   };
 
   // Forwards to |feed::TranslateWireResponse()| by default. Can be overridden
@@ -90,9 +93,15 @@ class FeedStream : public FeedStreamApi,
 
     void Populate(feedstore::Metadata metadata);
 
-    std::string GetConsistencyToken() const;
+    const std::string& GetConsistencyToken() const;
     void SetConsistencyToken(std::string consistency_token);
 
+    const std::string& GetSessionIdToken() const;
+    base::Time GetSessionIdExpiryTime() const;
+    void SetSessionId(std::string token, base::Time expiry_time);
+    void MaybeUpdateSessionId(base::Optional<std::string> token,
+                              const base::Clock* clock);
+
     LocalActionId GetNextActionId();
 
    private:
@@ -123,11 +132,12 @@ class FeedStream : public FeedStreamApi,
   // FeedStreamApi.
 
   bool IsActivityLoggingEnabled() const override;
+  std::string GetSessionId() const override;
   void AttachSurface(SurfaceInterface*) override;
   void DetachSurface(SurfaceInterface*) override;
   void SetArticlesListVisible(bool is_visible) override;
   bool IsArticlesListVisible() override;
-  std::string GetClientInstanceId() override;
+  std::string GetClientInstanceId() const override;
   void ExecuteRefreshTask() override;
   ImageFetchId FetchImage(
       const GURL& url,
@@ -148,6 +158,8 @@ class FeedStream : public FeedStreamApi,
   DebugStreamData GetDebugStreamData() override;
   void ForceRefreshForDebugging() override;
   std::string DumpStateForDebugging() override;
+  void SetForcedStreamUpdateForDebugging(
+      const feedui::StreamUpdate& stream_update) override;
 
   void ReportSliceViewed(SurfaceId surface_id,
                          const std::string& slice_id) override;
@@ -211,8 +223,11 @@ class FeedStream : public FeedStreamApi,
   FeedStore* GetStore() { return store_; }
   RequestThrottler* GetRequestThrottler() { return &request_throttler_; }
   Metadata* GetMetadata() { return &metadata_; }
+  const Metadata* GetMetadata() const { return &metadata_; }
   MetricsReporter* GetMetricsReporter() const { return metrics_reporter_; }
 
+  void PrefetchImage(const GURL& url);
+
   // Returns the time of the last content fetch.
   base::Time GetLastFetchTime();
 
@@ -252,7 +267,7 @@ class FeedStream : public FeedStreamApi,
 
   const base::Clock* GetClock() const { return clock_; }
   const base::TickClock* GetTickClock() const { return tick_clock_; }
-  RequestMetadata GetRequestMetadata();
+  RequestMetadata GetRequestMetadata(bool is_for_next_page) const;
 
   const WireResponseTranslator* GetWireResponseTranslator() const {
     return wire_response_translator_;
@@ -354,6 +369,12 @@ class FeedStream : public FeedStreamApi,
   // To allow tests to wait on task queue idle.
   base::RepeatingClosure idle_callback_;
 
+  // Stream update forced to use for new surfaces. This is provided in feed
+  // internals page for debugging purpose.
+  feedui::StreamUpdate forced_stream_update_for_debugging_;
+
+  NoticeCardTracker notice_card_tracker_;
+
   base::WeakPtrFactory<FeedStream> weak_ptr_factory_{this};
 };
 
diff --git a/chromium/components/feed/core/v2/feed_stream_unittest.cc b/chromium/components/feed/core/v2/feed_stream_unittest.cc
index ffbb96cc550..43831c0aa58 100644
--- a/chromium/components/feed/core/v2/feed_stream_unittest.cc
+++ b/chromium/components/feed/core/v2/feed_stream_unittest.cc
@@ -18,7 +18,7 @@
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/scoped_run_loop_timeout.h"
@@ -29,6 +29,7 @@
 #include "components/feed/core/common/pref_names.h"
 #include "components/feed/core/proto/v2/store.pb.h"
 #include "components/feed/core/proto/v2/ui.pb.h"
+#include "components/feed/core/proto/v2/wire/chrome_client_info.pb.h"
 #include "components/feed/core/proto/v2/wire/request.pb.h"
 #include "components/feed/core/proto/v2/wire/there_and_back_again_data.pb.h"
 #include "components/feed/core/proto/v2/xsurface.pb.h"
@@ -303,6 +304,7 @@ class TestFeedNetwork : public FeedNetwork {
     result.response_info.status_code = 200;
     result.response_info.response_body_bytes = 100;
     result.response_info.fetch_duration = base::TimeDelta::FromMilliseconds(42);
+    result.response_info.was_signed_in = true;
     if (injected_response_) {
       result.response_body = std::make_unique<feedwire::Response>(
           std::move(injected_response_.value()));
@@ -387,9 +389,12 @@ class TestWireResponseTranslator : public FeedStream::WireResponseTranslator {
     return FeedStream::WireResponseTranslator::TranslateWireResponse(
         std::move(response), source, was_signed_in_request, current_time);
   }
-  void InjectResponse(std::unique_ptr<StreamModelUpdateRequest> response) {
+  void InjectResponse(std::unique_ptr<StreamModelUpdateRequest> response,
+                      base::Optional<std::string> session_id = base::nullopt) {
+    DCHECK(!response->stream_data.signed_in() || !session_id);
     RefreshResponseData data;
     data.model_update_request = std::move(response);
+    data.session_id = std::move(session_id);
     InjectResponse(std::move(data));
   }
   void InjectResponse(RefreshResponseData response_data) {
@@ -573,10 +578,7 @@ class FeedStreamTest : public testing::Test, public FeedStream::Delegate {
     CreateStream();
   }
 
-  virtual void SetupFeatures() {
-    scoped_feature_list_.InitAndDisableFeature(
-        feed::kInterestFeedV2ClicksAndViewsConditionalUpload);
-  }
+  virtual void SetupFeatures() {}
 
   void TearDown() override {
     // Ensure the task queue can return to idle. Failure to do so may be due
@@ -600,6 +602,10 @@ class FeedStreamTest : public testing::Test, public FeedStream::Delegate {
   std::string GetLanguageTag() override { return "en-US"; }
   void ClearAll() override {}
   bool IsSignedIn() override { return is_signed_in_; }
+  void PrefetchImage(const GURL& url) override {
+    prefetched_images_.push_back(url);
+    prefetch_image_call_count_++;
+  }
 
   // For tests.
 
@@ -690,6 +696,8 @@ class FeedStreamTest : public testing::Test, public FeedStream::Delegate {
   bool is_offline_ = false;
   bool is_signed_in_ = true;
   base::test::ScopedFeatureList scoped_feature_list_;
+  int prefetch_image_call_count_ = 0;
+  std::vector<GURL> prefetched_images_;
 };
 
 class FeedStreamConditionalActionsUploadTest : public FeedStreamTest {
@@ -742,6 +750,21 @@ TEST_F(FeedStreamTest, BackgroundRefreshSuccess) {
   EXPECT_EQ(1, prefetch_service_.NewSuggestionsAvailableCallCount());
 }
 
+TEST_F(FeedStreamTest, BackgroundRefreshPrefetchesImages) {
+  // Trigger a background refresh.
+  response_translator_.InjectResponse(MakeTypicalInitialModelState());
+  stream_->ExecuteRefreshTask();
+  EXPECT_EQ(0, prefetch_image_call_count_);
+  WaitForIdleTaskQueue();
+
+  std::vector<GURL> expected_fetches(
+      {GURL("http://image0/"), GURL("http://favicon0/"), GURL("http://image1/"),
+       GURL("http://favicon1/")});
+  // Verify that images were prefetched.
+  EXPECT_EQ(4, prefetch_image_call_count_);
+  EXPECT_EQ(expected_fetches, prefetched_images_);
+}
+
 TEST_F(FeedStreamTest, BackgroundRefreshNotAttemptedWhenModelIsLoading) {
   response_translator_.InjectResponse(MakeTypicalInitialModelState());
   TestSurface surface(stream_.get());
@@ -1089,14 +1112,78 @@ TEST_F(FeedStreamTest, LoadStreamAfterEulaIsAccepted) {
 
 TEST_F(FeedStreamTest, ForceSignedOutRequestAfterHistoryIsDeleted) {
   stream_->OnAllHistoryDeleted();
+
+  const std::string kSessionId = "session-id";
+
+  // This test injects response post translation/parsing. We have to configure
+  // the response data that should come out of the translator, which should
+  // mark the request/response as having been made from the signed-out state.
+  StreamModelUpdateRequestGenerator model_generator;
+  model_generator.signed_in = false;
+
+  // Advance the clock, but not past the end of the forced-signed-out period.
   task_environment_.FastForwardBy(kSuppressRefreshDuration -
                                   base::TimeDelta::FromSeconds(1));
-  response_translator_.InjectResponse(MakeTypicalInitialModelState());
+
+  // Refresh the feed, queuing up a signed-out response.
+  response_translator_.InjectResponse(model_generator.MakeFirstPage(),
+                                      kSessionId);
   TestSurface surface(stream_.get());
   WaitForIdleTaskQueue();
 
+  // Validate that the network request was sent as signed out.
+  ASSERT_EQ(1, network_.send_query_call_count);
+  EXPECT_TRUE(network_.forced_signed_out_request);
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .chrome_client_info()
+                  .session_id()
+                  .empty());
+
+  // Validate the downstream consumption of the response.
   EXPECT_EQ("loading -> 2 slices", surface.DescribeUpdates());
+  EXPECT_EQ(kSessionId, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_FALSE(stream_->GetModel()->signed_in());
+
+  // Advance the clock beyond the forced signed out period.
+  task_environment_.FastForwardBy(base::TimeDelta::FromSeconds(2));
+  EXPECT_FALSE(stream_->GetModel()->signed_in());
+
+  // Requests for subsequent pages continue the use existing session.
+  // Subsequent responses may omit the session id.
+  response_translator_.InjectResponse(model_generator.MakeNextPage());
+  stream_->LoadMore(surface.GetSurfaceId(), base::DoNothing());
+  WaitForIdleTaskQueue();
+
+  // Validate that the network request was sent as signed out and
+  // contained the session id.
+  ASSERT_EQ(2, network_.send_query_call_count);
   EXPECT_TRUE(network_.forced_signed_out_request);
+  EXPECT_EQ(kSessionId, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(network_.query_request_sent->feed_request()
+                .client_info()
+                .chrome_client_info()
+                .session_id(),
+            kSessionId);
+
+  // The model should still be in the signed-out state.
+  EXPECT_FALSE(stream_->GetModel()->signed_in());
+
+  // Force a refresh of the feed by clearing the cache. The request for the
+  // first page should revert back to signed-in. The response data will denote
+  // a signed-in response with no session_id.
+  model_generator.signed_in = true;
+  response_translator_.InjectResponse(model_generator.MakeFirstPage());
+  stream_->OnCacheDataCleared();
+  WaitForIdleTaskQueue();
+
+  // Validate that a signed-in request was sent.
+  ASSERT_EQ(3, network_.send_query_call_count);
+  EXPECT_FALSE(network_.forced_signed_out_request);
+
+  // The model should now be in the signed-in state.
+  EXPECT_TRUE(stream_->GetModel()->signed_in());
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdToken().empty());
 }
 
 TEST_F(FeedStreamTest, AllowSignedInRequestAfterHistoryIsDeletedAfterDelay) {
@@ -1109,6 +1196,7 @@ TEST_F(FeedStreamTest, AllowSignedInRequestAfterHistoryIsDeletedAfterDelay) {
 
   EXPECT_EQ("loading -> 2 slices", surface.DescribeUpdates());
   EXPECT_FALSE(network_.forced_signed_out_request);
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdToken().empty());
 }
 
 TEST_F(FeedStreamTest, ShouldMakeFeedQueryRequestConsumesQuota) {
@@ -1809,6 +1897,29 @@ TEST_F(FeedStreamTest, LoadStreamUpdateNoticeCardFulfillmentHistogram) {
                                1, 1);
 }
 
+TEST_F(FeedStreamConditionalActionsUploadTest,
+       DontTriggerActionsUploadWhenWasNotSignedIn) {
+  auto update_request = MakeTypicalInitialModelState();
+  update_request->stream_data.set_signed_in(false);
+  response_translator_.InjectResponse(std::move(update_request));
+  TestSurface surface(stream_.get());
+  WaitForIdleTaskQueue();
+
+  // Try to reach conditions.
+  stream_->ReportSliceViewed(
+      surface.GetSurfaceId(),
+      surface.initial_state->updated_slices(1).slice().slice_id());
+
+  // Try to trigger an upload through a query.
+  stream_->OnEnterBackground();
+  WaitForIdleTaskQueue();
+
+  // Verify that even if the conditions were reached, the pref that enables the
+  // upload wasn't set to true because the latest refresh request wasn't signed
+  // in.
+  ASSERT_FALSE(stream_->CanUploadActions());
+}
+
 TEST_F(FeedStreamTest, LoadStreamFromNetworkUploadsActions) {
   stream_->UploadAction(MakeFeedAction(99ul), false, base::DoNothing());
   WaitForIdleTaskQueue();
@@ -1893,7 +2004,14 @@ TEST_F(FeedStreamTest, LoadMoreUpdatesIsActivityLoggingEnabled) {
         CallbackReceiver<bool> callback;
         stream_->LoadMore(surface.GetSurfaceId(), callback.Bind());
         WaitForIdleTaskQueue();
-        EXPECT_EQ(stream_->IsActivityLoggingEnabled(), signed_in && waa_on);
+        EXPECT_EQ(
+            stream_->IsActivityLoggingEnabled(),
+            (signed_in && waa_on) ||
+                (!signed_in && GetFeedConfig().send_signed_out_session_logs))
+            << "signed_in=" << signed_in << " waa_on=" << waa_on
+            << " privacy_notice_fulfilled=" << privacy_notice_fulfilled
+            << " send_signed_out_session_logs="
+            << GetFeedConfig().send_signed_out_session_logs;
       }
     }
   }
@@ -1911,7 +2029,6 @@ TEST_F(FeedStreamConditionalActionsUploadTest,
   response_translator_.InjectResponse(MakeTypicalNextPageState(
       /* first_cluster_id= */ 0,
       /* last_added_time= */ kTestTimeEpoch,
-      /* signed_in= */ true,
       /* logging_enabled= */ true,
       /* privacy_notice_fulfilled= */ false));
 
@@ -2055,7 +2172,8 @@ TEST_F(FeedStreamTest, UploadActionsErasesStaleActionsByAttempts) {
 TEST_F(FeedStreamTest, MetadataLoadedWhenDatabaseInitialized) {
   ASSERT_TRUE(stream_->GetMetadata());
 
-  // Set the token and increment next action ID.
+  const auto kExpiry = kTestTimeEpoch + base::TimeDelta::FromDays(1234);
+  stream_->GetMetadata()->SetSessionId("session-id", kExpiry);
   stream_->GetMetadata()->SetConsistencyToken("token");
   EXPECT_EQ(1, stream_->GetMetadata()->GetNextActionId().GetUnsafeValue());
 
@@ -2063,6 +2181,8 @@ TEST_F(FeedStreamTest, MetadataLoadedWhenDatabaseInitialized) {
   CreateStream();
 
   ASSERT_TRUE(stream_->GetMetadata());
+  EXPECT_EQ("session-id", stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kExpiry, stream_->GetMetadata()->GetSessionIdExpiryTime());
   EXPECT_EQ("token", stream_->GetMetadata()->GetConsistencyToken());
   EXPECT_EQ(2, stream_->GetMetadata()->GetNextActionId().GetUnsafeValue());
 }
@@ -2335,6 +2455,13 @@ TEST_F(FeedStreamTest, SendsClientInstanceId) {
                                       .client_instance_id();
   EXPECT_NE("", first_instance_id);
 
+  // No signed-out session id was in the request.
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .chrome_client_info()
+                  .session_id()
+                  .empty());
+
   // LoadMore, and verify the same token is used.
   response_translator_.InjectResponse(MakeTypicalNextPageState(2));
   stream_->LoadMore(surface.GetSurfaceId(), base::DoNothing());
@@ -2345,15 +2472,311 @@ TEST_F(FeedStreamTest, SendsClientInstanceId) {
                                    .client_info()
                                    .client_instance_id());
 
+  // No signed-out session id was in the request.
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .chrome_client_info()
+                  .session_id()
+                  .empty());
+
   // Trigger a ClearAll to verify the instance ID changes.
   stream_->OnSignedOut();
   WaitForIdleTaskQueue();
 
+  EXPECT_FALSE(stream_->GetModel());
+  const bool is_for_next_page = false;  // No model so no first page yet.
   const std::string new_instance_id =
-      stream_->GetRequestMetadata().client_instance_id;
+      stream_->GetRequestMetadata(is_for_next_page).client_instance_id;
   ASSERT_NE("", new_instance_id);
   ASSERT_NE(first_instance_id, new_instance_id);
 }
 
+TEST_F(FeedStreamTest, LoadStreamSendsNoticeCardAcknowledgement) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      feed::kInterestFeedNoticeCardAutoDismiss);
+
+  store_->OverwriteStream(MakeTypicalInitialModelState(), base::DoNothing());
+  TestSurface surface(stream_.get());
+  WaitForIdleTaskQueue();
+
+  // Generate 3 view actions and 1 click action to trigger the acknowledgement
+  // of the notice card.
+  const int notice_card_index = 0;
+  std::string slice_id =
+      surface.initial_state->updated_slices(notice_card_index)
+          .slice()
+          .slice_id();
+  stream_->ReportSliceViewed(surface.GetSurfaceId(), slice_id);
+  stream_->ReportSliceViewed(surface.GetSurfaceId(), slice_id);
+  stream_->ReportSliceViewed(surface.GetSurfaceId(), slice_id);
+  stream_->ReportOpenAction(slice_id);
+
+  response_translator_.InjectResponse(MakeTypicalInitialModelState());
+  refresh_scheduler_.Clear();
+  stream_->UnloadModel();
+  stream_->ExecuteRefreshTask();
+  WaitForIdleTaskQueue();
+
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .feed_query()
+                  .chrome_fulfillment_info()
+                  .notice_card_acknowledged());
+}
+
+TEST_F(FeedStreamTest, GetSetAndUpdateSessionId) {
+  const std::string kToken1 = "token1";
+  const std::string kToken2 = "token2";
+  const base::Time kExpiryTime1 =
+      kTestTimeEpoch + base::TimeDelta::FromHours(2);
+  const base::Time kExpiryTime2 =
+      kTestTimeEpoch + GetFeedConfig().session_id_max_age;
+  ASSERT_NE(kExpiryTime1, kExpiryTime2);
+
+  // The stream metadata is initialized with an empty token and expiry time.
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdToken().empty());
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdExpiryTime().is_null());
+
+  // Verify that directly calling SetSessionId works as expected.
+  stream_->GetMetadata()->SetSessionId(kToken1, kExpiryTime1);
+  EXPECT_EQ(kToken1, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kExpiryTime1, stream_->GetMetadata()->GetSessionIdExpiryTime());
+
+  // Updating the token with nullopt is a NOP.
+  stream_->GetMetadata()->MaybeUpdateSessionId(base::nullopt,
+                                               stream_->GetClock());
+  EXPECT_EQ(kToken1, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kExpiryTime1, stream_->GetMetadata()->GetSessionIdExpiryTime());
+
+  // Updating the token with the same value is a NOP.
+  stream_->GetMetadata()->MaybeUpdateSessionId(kToken1, stream_->GetClock());
+  EXPECT_EQ(kToken1, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kExpiryTime1, stream_->GetMetadata()->GetSessionIdExpiryTime());
+
+  // Updating the token with a different value resets the token and assigns a
+  // new expiry time.
+  stream_->GetMetadata()->MaybeUpdateSessionId(kToken2, stream_->GetClock());
+  EXPECT_EQ(kToken2, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kExpiryTime2, stream_->GetMetadata()->GetSessionIdExpiryTime());
+
+  // Updating the token with the empty string clears its value.
+  stream_->GetMetadata()->MaybeUpdateSessionId("", stream_->GetClock());
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdToken().empty());
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdExpiryTime().is_null());
+}
+
+TEST_F(FeedStreamTest, SignedOutSessionIdConsistency) {
+  const std::string kSessionToken1("session-token-1");
+  const std::string kSessionToken2("session-token-2");
+
+  is_signed_in_ = false;
+
+  StreamModelUpdateRequestGenerator model_generator;
+  model_generator.signed_in = false;
+
+  // (1) Do an initial load of the store
+  //     - this should trigger a network request
+  //     - the request should not include client-instance-id
+  //     - the request should not include a session-id
+  //     - the stream should capture the session-id token from the response
+  response_translator_.InjectResponse(model_generator.MakeFirstPage(),
+                                      kSessionToken1);
+  TestSurface surface(stream_.get());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(1, network_.send_query_call_count);
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .client_instance_id()
+                  .empty());
+  EXPECT_FALSE(network_.query_request_sent->feed_request()
+                   .client_info()
+                   .has_chrome_client_info());
+  EXPECT_EQ(kSessionToken1, stream_->GetMetadata()->GetSessionIdToken());
+  const base::Time kSessionToken1ExpiryTime =
+      stream_->GetMetadata()->GetSessionIdExpiryTime();
+
+  // (2) LoadMore: the server returns the same session-id token
+  //     - this should trigger a network request
+  //     - the request should not include client-instance-id
+  //     - the request should include the first session-id
+  //     - the stream should retain the first session-id
+  //     - the session-id's expiry time should be unchanged
+  task_environment_.FastForwardBy(base::TimeDelta::FromSeconds(1));
+  response_translator_.InjectResponse(model_generator.MakeNextPage(2),
+                                      kSessionToken1);
+  stream_->LoadMore(surface.GetSurfaceId(), base::DoNothing());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(2, network_.send_query_call_count);
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .client_instance_id()
+                  .empty());
+  EXPECT_EQ(kSessionToken1, network_.query_request_sent->feed_request()
+                                .client_info()
+                                .chrome_client_info()
+                                .session_id());
+  EXPECT_EQ(kSessionToken1, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kSessionToken1ExpiryTime,
+            stream_->GetMetadata()->GetSessionIdExpiryTime());
+
+  // (3) LoadMore: the server omits returning a session-id token
+  //     - this should trigger a network request
+  //     - the request should not include client-instance-id
+  //     - the request should include the first session-id
+  //     - the stream should retain the first session-id
+  //     - the session-id's expiry time should be unchanged
+  task_environment_.FastForwardBy(base::TimeDelta::FromSeconds(1));
+  response_translator_.InjectResponse(model_generator.MakeNextPage(3));
+  stream_->LoadMore(surface.GetSurfaceId(), base::DoNothing());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(3, network_.send_query_call_count);
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .client_instance_id()
+                  .empty());
+  EXPECT_EQ(kSessionToken1, network_.query_request_sent->feed_request()
+                                .client_info()
+                                .chrome_client_info()
+                                .session_id());
+  EXPECT_EQ(kSessionToken1, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kSessionToken1ExpiryTime,
+            stream_->GetMetadata()->GetSessionIdExpiryTime());
+
+  // (4) LoadMore: the server returns new session id.
+  //     - this should trigger a network request
+  //     - the request should not include client-instance-id
+  //     - the request should include the first session-id
+  //     - the stream should retain the second session-id
+  //     - the new session-id's expiry time should be updated
+  task_environment_.FastForwardBy(base::TimeDelta::FromSeconds(1));
+  response_translator_.InjectResponse(model_generator.MakeNextPage(4),
+                                      kSessionToken2);
+  stream_->LoadMore(surface.GetSurfaceId(), base::DoNothing());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(4, network_.send_query_call_count);
+  EXPECT_TRUE(network_.query_request_sent->feed_request()
+                  .client_info()
+                  .client_instance_id()
+                  .empty());
+  EXPECT_EQ(kSessionToken1, network_.query_request_sent->feed_request()
+                                .client_info()
+                                .chrome_client_info()
+                                .session_id());
+  EXPECT_EQ(kSessionToken2, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kSessionToken1ExpiryTime + base::TimeDelta::FromSeconds(3),
+            stream_->GetMetadata()->GetSessionIdExpiryTime());
+}
+
+TEST_F(FeedStreamTest, ClearAllResetsSessionId) {
+  is_signed_in_ = false;
+
+  // Initialize a session id.
+  stream_->GetMetadata()->MaybeUpdateSessionId("session-id",
+                                               stream_->GetClock());
+  ASSERT_FALSE(stream_->GetMetadata()->GetSessionIdToken().empty());
+  ASSERT_FALSE(stream_->GetMetadata()->GetSessionIdExpiryTime().is_null());
+
+  // Trigger a ClearAll.
+  stream_->OnCacheDataCleared();
+  WaitForIdleTaskQueue();
+
+  // Session-ID should be wiped.
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdToken().empty());
+  EXPECT_TRUE(stream_->GetMetadata()->GetSessionIdExpiryTime().is_null());
+}
+
+TEST_F(FeedStreamTest, SignedOutSessionIdExpiry) {
+  const std::string kSessionToken1("session-token-1");
+  const std::string kSessionToken2("session-token-2");
+
+  is_signed_in_ = false;
+
+  StreamModelUpdateRequestGenerator model_generator;
+  model_generator.signed_in = false;
+
+  // (1) Do an initial load of the store
+  //     - this should trigger a network request
+  //     - the request should not include a session-id
+  //     - the stream should capture the session-id token from the response
+  response_translator_.InjectResponse(model_generator.MakeFirstPage(),
+                                      kSessionToken1);
+  TestSurface surface(stream_.get());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(1, network_.send_query_call_count);
+  EXPECT_FALSE(network_.query_request_sent->feed_request()
+                   .client_info()
+                   .has_chrome_client_info());
+  EXPECT_EQ(kSessionToken1, stream_->GetMetadata()->GetSessionIdToken());
+
+  // (2) Reload the stream from the network:
+  //     - Detach the surface, advance the clock beyond the stale content
+  //       threshold, re-attach the surface.
+  //     - this should trigger a network request
+  //     - the request should include kSessionToken1
+  //     - the stream should retain the original session-id
+  surface.Detach();
+  task_environment_.FastForwardBy(GetFeedConfig().stale_content_threshold +
+                                  base::TimeDelta::FromSeconds(1));
+  response_translator_.InjectResponse(model_generator.MakeFirstPage());
+  surface.Attach(stream_.get());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(2, network_.send_query_call_count);
+  EXPECT_EQ(kSessionToken1, network_.query_request_sent->feed_request()
+                                .client_info()
+                                .chrome_client_info()
+                                .session_id());
+  EXPECT_EQ(kSessionToken1, stream_->GetMetadata()->GetSessionIdToken());
+
+  // (3) Reload the stream from the network:
+  //     - Detach the surface, advance the clock beyond the session id max age
+  //       threshold, re-attach the surface.
+  //     - this should trigger a network request
+  //     - the request should not include a session-id
+  //     - the stream should get a new session-id
+  surface.Detach();
+  task_environment_.FastForwardBy(GetFeedConfig().session_id_max_age -
+                                  GetFeedConfig().stale_content_threshold);
+  ASSERT_LT(stream_->GetMetadata()->GetSessionIdExpiryTime(),
+            task_environment_.GetMockClock()->Now());
+  response_translator_.InjectResponse(model_generator.MakeFirstPage(),
+                                      kSessionToken2);
+  surface.Attach(stream_.get());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(3, network_.send_query_call_count);
+  EXPECT_FALSE(network_.query_request_sent->feed_request()
+                   .client_info()
+                   .has_chrome_client_info());
+  EXPECT_EQ(kSessionToken2, stream_->GetMetadata()->GetSessionIdToken());
+}
+
+TEST_F(FeedStreamTest, SessionIdPersistsAcrossStreamLoads) {
+  const std::string kSessionToken("session-token-ftw");
+  const base::Time kExpiryTime =
+      kTestTimeEpoch + GetFeedConfig().session_id_max_age;
+
+  StreamModelUpdateRequestGenerator model_generator;
+  model_generator.signed_in = false;
+  is_signed_in_ = false;
+
+  // (1) Do an initial load of the store
+  //     - this should trigger a network request
+  //     - the stream should capture the session-id token from the response
+  response_translator_.InjectResponse(model_generator.MakeFirstPage(),
+                                      kSessionToken);
+  TestSurface surface(stream_.get());
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(1, network_.send_query_call_count);
+
+  // (2) Reload the metadata from disk.
+  //     - the network query call count should be unchanged
+  //     - the session token and expiry time should have been reloaded.
+  surface.Detach();
+  CreateStream();
+  WaitForIdleTaskQueue();
+  ASSERT_EQ(1, network_.send_query_call_count);
+  EXPECT_EQ(kSessionToken, stream_->GetMetadata()->GetSessionIdToken());
+  EXPECT_EQ(kExpiryTime, stream_->GetMetadata()->GetSessionIdExpiryTime());
+}
+
 }  // namespace
 }  // namespace feed
diff --git a/chromium/components/feed/core/v2/image_fetcher_unittest.cc b/chromium/components/feed/core/v2/image_fetcher_unittest.cc
index ba2dbe4f548..185945c7d89 100644
--- a/chromium/components/feed/core/v2/image_fetcher_unittest.cc
+++ b/chromium/components/feed/core/v2/image_fetcher_unittest.cc
@@ -10,7 +10,7 @@
 #include "base/bind.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
-#include "base/test/bind_test_util.h"
+#include "base/test/bind.h"
 #include "base/test/metrics/histogram_tester.h"
 #include "base/test/task_environment.h"
 #include "components/feed/core/v2/public/types.h"
diff --git a/chromium/components/feed/core/v2/metrics_reporter.cc b/chromium/components/feed/core/v2/metrics_reporter.cc
index d23a99f17b9..df136e67a40 100644
--- a/chromium/components/feed/core/v2/metrics_reporter.cc
+++ b/chromium/components/feed/core/v2/metrics_reporter.cc
@@ -11,12 +11,13 @@
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
+#include "components/feed/core/v2/common_enums.h"
 #include "components/feed/core/v2/prefs.h"
 
 namespace feed {
 namespace {
-using feed::internal::FeedEngagementType;
-using feed::internal::FeedUserActionType;
+using feed::FeedEngagementType;
+using feed::FeedUserActionType;
 const int kMaxSuggestionsTotal = 50;
 // Maximum time to wait before declaring a load operation failed.
 // For both ContentSuggestions.Feed.UserJourney.OpenFeed
diff --git a/chromium/components/feed/core/v2/metrics_reporter.h b/chromium/components/feed/core/v2/metrics_reporter.h
index 31489456ead..21515c8697f 100644
--- a/chromium/components/feed/core/v2/metrics_reporter.h
+++ b/chromium/components/feed/core/v2/metrics_reporter.h
@@ -5,6 +5,7 @@
 #ifndef COMPONENTS_FEED_CORE_V2_METRICS_REPORTER_H_
 #define COMPONENTS_FEED_CORE_V2_METRICS_REPORTER_H_
 
+#include <climits>
 #include <map>
 
 #include "base/memory/weak_ptr.h"
@@ -17,50 +18,16 @@ namespace base {
 class TickClock;
 }  // namespace base
 namespace feed {
-namespace internal {
-// This enum is used for a UMA histogram. Keep in sync with FeedEngagementType
-// in enums.xml.
-enum class FeedEngagementType {
-  kFeedEngaged = 0,
-  kFeedEngagedSimple = 1,
-  kFeedInteracted = 2,
-  kDeprecatedFeedScrolled = 3,
-  kFeedScrolled = 4,
-  kMaxValue = FeedEngagementType::kFeedScrolled,
-};
-
-// This enum must match FeedUserActionType in enums.xml.
-// Note that most of these have a corresponding UserMetricsAction reported here.
-// Exceptions are described below.
-enum class FeedUserActionType {
-  kTappedOnCard = 0,
-  // This is not an actual user action, so there will be no UserMetricsAction
-  // reported for this.
-  kShownCard = 1,
-  kTappedSendFeedback = 2,
-  kTappedLearnMore = 3,
-  kTappedHideStory = 4,
-  kTappedNotInterestedIn = 5,
-  kTappedManageInterests = 6,
-  kTappedDownload = 7,
-  kTappedOpenInNewTab = 8,
-  kOpenedContextMenu = 9,
-  // User action not reported here. See Suggestions.SurfaceVisible.
-  kOpenedFeedSurface = 10,
-  kTappedOpenInNewIncognitoTab = 11,
-  kEphemeralChange = 12,
-  kEphemeralChangeRejected = 13,
-  kTappedTurnOn = 14,
-  kTappedTurnOff = 15,
-  kMaxValue = kTappedTurnOff,
-};
-
-}  // namespace internal
 
 // Reports UMA metrics for feed.
 // Note this is inherited only for testing.
 class MetricsReporter {
  public:
+  // For 'index_in_stream' parameters, when the card index is unknown.
+  // This is most likely to happen when the action originates from the bottom
+  // sheet.
+  static const int kUnknownCardIndex = INT_MAX;
+
   explicit MetricsReporter(const base::TickClock* clock,
                            PrefService* profile_prefs);
   virtual ~MetricsReporter();
diff --git a/chromium/components/feed/core/v2/metrics_reporter_unittest.cc b/chromium/components/feed/core/v2/metrics_reporter_unittest.cc
index c38bdb43cad..e768420fa4c 100644
--- a/chromium/components/feed/core/v2/metrics_reporter_unittest.cc
+++ b/chromium/components/feed/core/v2/metrics_reporter_unittest.cc
@@ -12,12 +12,11 @@
 #include "base/test/task_environment.h"
 #include "components/feed/core/common/pref_names.h"
 #include "components/feed/core/shared_prefs/pref_names.h"
+#include "components/feed/core/v2/common_enums.h"
 #include "components/prefs/testing_pref_service.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace feed {
-using feed::internal::FeedEngagementType;
-using feed::internal::FeedUserActionType;
 constexpr SurfaceId kSurfaceId = SurfaceId(5);
 const base::TimeDelta kEpsilon = base::TimeDelta::FromMilliseconds(1);
 
diff --git a/chromium/components/feed/core/v2/notice_card_tracker.cc b/chromium/components/feed/core/v2/notice_card_tracker.cc
new file mode 100644
index 00000000000..cb318c8678e
--- /dev/null
+++ b/chromium/components/feed/core/v2/notice_card_tracker.cc
@@ -0,0 +1,97 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/feed/core/v2/notice_card_tracker.h"
+
+#include "components/feed/core/v2/prefs.h"
+#include "components/feed/feed_feature_list.h"
+#include "components/prefs/pref_service.h"
+
+namespace feed {
+namespace {
+
+int GetNoticeCardIndex() {
+  // Infer that the notice card is at the 2nd position when the feature related
+  // to putting the notice card at the second position is enabled.
+  if (base::FeatureList::IsEnabled(
+          feed::kInterestFeedV2ClicksAndViewsConditionalUpload)) {
+    return 1;
+  }
+  return 0;
+}
+
+}  // namespace
+
+NoticeCardTracker::NoticeCardTracker(PrefService* profile_prefs)
+    : profile_prefs_(profile_prefs) {
+  DCHECK(profile_prefs_);
+}
+
+void NoticeCardTracker::OnSliceViewed(int index) {
+  MaybeUpdateNoticeCardViewsCount(index);
+}
+
+void NoticeCardTracker::OnOpenAction(int index) {
+  MaybeUpdateNoticeCardClicksCount(index);
+}
+
+bool NoticeCardTracker::HasAcknowledgedNoticeCard() const {
+  if (!base::FeatureList::IsEnabled(feed::kInterestFeedNoticeCardAutoDismiss))
+    return false;
+
+  int views_count_threshold = base::GetFieldTrialParamByFeatureAsInt(
+      feed::kInterestFeedNoticeCardAutoDismiss,
+      kNoticeCardViewsCountThresholdParamName, 3);
+  DCHECK(views_count_threshold >= 0);
+  int clicks_count_threshold = base::GetFieldTrialParamByFeatureAsInt(
+      feed::kInterestFeedNoticeCardAutoDismiss,
+      kNoticeCardClicksCountThresholdParamName, 1);
+  DCHECK(clicks_count_threshold >= 0);
+
+  DCHECK(views_count_threshold > 0 || clicks_count_threshold > 0)
+      << "all notice card auto-dismiss thresholds are set to 0 when there "
+         "should be at least one threshold above 0";
+
+  if (views_count_threshold > 0 &&
+      prefs::GetNoticeCardViewsCount(*profile_prefs_) >=
+          views_count_threshold) {
+    return true;
+  }
+
+  if (clicks_count_threshold > 0 &&
+      prefs::GetNoticeCardClicksCount(*profile_prefs_) >=
+          clicks_count_threshold) {
+    return true;
+  }
+
+  return false;
+}
+
+bool NoticeCardTracker::HasNoticeCardActionsCountPrerequisites(int index) {
+  if (!base::FeatureList::IsEnabled(feed::kInterestFeedNoticeCardAutoDismiss))
+    return false;
+
+  if (!prefs::GetLastFetchHadNoticeCard(*profile_prefs_)) {
+    return false;
+  }
+
+  if (index != GetNoticeCardIndex()) {
+    return false;
+  }
+  return true;
+}
+void NoticeCardTracker::MaybeUpdateNoticeCardViewsCount(int index) {
+  if (!HasNoticeCardActionsCountPrerequisites(index))
+    return;
+
+  prefs::IncrementNoticeCardViewsCount(*profile_prefs_);
+}
+void NoticeCardTracker::MaybeUpdateNoticeCardClicksCount(int index) {
+  if (!HasNoticeCardActionsCountPrerequisites(index))
+    return;
+
+  prefs::IncrementNoticeCardClicksCount(*profile_prefs_);
+}
+
+}  // namespace feed
\ No newline at end of file
diff --git a/chromium/components/feed/core/v2/notice_card_tracker.h b/chromium/components/feed/core/v2/notice_card_tracker.h
new file mode 100644
index 00000000000..db9f71815d1
--- /dev/null
+++ b/chromium/components/feed/core/v2/notice_card_tracker.h
@@ -0,0 +1,47 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_FEED_CORE_V2_NOTICE_CARD_TRACKER_H_
+#define COMPONENTS_FEED_CORE_V2_NOTICE_CARD_TRACKER_H_
+
+class PrefService;
+
+namespace feed {
+
+constexpr char kNoticeCardViewsCountThresholdParamName[] =
+    "notice-card-views-count-threshold";
+constexpr char kNoticeCardClicksCountThresholdParamName[] =
+    "notice-card-clicks-count-threshold";
+
+// Tracker for the notice card related actions that also provide signals based
+// on those.
+class NoticeCardTracker {
+ public:
+  explicit NoticeCardTracker(PrefService* profile_prefs);
+
+  NoticeCardTracker(const NoticeCardTracker&) = delete;
+  NoticeCardTracker& operator=(const NoticeCardTracker&) = delete;
+
+  // Capture the actions.
+
+  void OnSliceViewed(int index);
+  void OnOpenAction(int index);
+
+  // Get signals based on the actions.
+
+  // Indicates whether there were enough views or clicks done on the notice
+  // card to consider it as acknowledged by the user.
+  bool HasAcknowledgedNoticeCard() const;
+
+ private:
+  bool HasNoticeCardActionsCountPrerequisites(int index);
+  void MaybeUpdateNoticeCardViewsCount(int index);
+  void MaybeUpdateNoticeCardClicksCount(int index);
+
+  PrefService* profile_prefs_;
+};
+
+}  // namespace feed
+
+#endif  // COMPONENTS_FEED_CORE_V2_NOTICE_CARD_TRACKER_H_
\ No newline at end of file
diff --git a/chromium/components/feed/core/v2/notice_card_tracker_unittest.cc b/chromium/components/feed/core/v2/notice_card_tracker_unittest.cc
new file mode 100644
index 00000000000..60efb9d10aa
--- /dev/null
+++ b/chromium/components/feed/core/v2/notice_card_tracker_unittest.cc
@@ -0,0 +1,151 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/feed/core/v2/notice_card_tracker.h"
+
+#include "base/test/scoped_feature_list.h"
+#include "components/feed/core/common/pref_names.h"
+#include "components/feed/core/v2/prefs.h"
+#include "components/feed/feed_feature_list.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/testing_pref_service.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace feed {
+namespace {
+
+class NoticeCardTrackerTest : public testing::Test {
+ public:
+  void SetUp() override {
+    feed::RegisterProfilePrefs(profile_prefs_.registry());
+    ;
+  }
+
+ protected:
+  TestingPrefServiceSimple profile_prefs_;
+};
+
+TEST_F(NoticeCardTrackerTest,
+       TrackingNoticeCardActionsDoesntUpdateCountsWhenNoNoticeCard) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      feed::kInterestFeedNoticeCardAutoDismiss);
+  NoticeCardTracker tracker(&profile_prefs_);
+
+  prefs::SetLastFetchHadNoticeCard(profile_prefs_, false);
+
+  // Generate enough views to reach the acknowlegement threshold, but there was
+  // no notice card in the feed.
+  const int notice_card_index = 0;
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+
+  EXPECT_FALSE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest,
+       TrackingNoticeCardActionsDoesntUpdateCountsForNonNoticeCard) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      feed::kInterestFeedNoticeCardAutoDismiss);
+  NoticeCardTracker tracker(&profile_prefs_);
+
+  // Generate enough views to reach the acknowlegement threshold, but the views
+  // were not on the notice card.
+  const int non_notice_card_index = 1;
+  tracker.OnSliceViewed(non_notice_card_index);
+  tracker.OnSliceViewed(non_notice_card_index);
+  tracker.OnSliceViewed(non_notice_card_index);
+
+  EXPECT_FALSE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest,
+       AcknowledgedNoticeCardWhenEnoughViewsAndNoticeCardAt1stPos) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      feed::kInterestFeedNoticeCardAutoDismiss);
+  NoticeCardTracker tracker(&profile_prefs_);
+
+  const int notice_card_index = 0;
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+
+  EXPECT_TRUE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest,
+       AcknowledgedNoticeCardWhenEnoughViewsAndNoticeCardAt2ndPos) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitWithFeatures(
+      /*enabled_features=*/{feed::kInterestFeedNoticeCardAutoDismiss,
+                            feed::
+                                kInterestFeedV2ClicksAndViewsConditionalUpload},
+      /*disabled_features=*/{});
+  NoticeCardTracker tracker(&profile_prefs_);
+
+  const int notice_card_index = 1;
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+
+  EXPECT_TRUE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest,
+       DontAcknowledgedNoticeCardWhenNotEnoughViewsNorClicks) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      feed::kInterestFeedNoticeCardAutoDismiss);
+  NoticeCardTracker tracker(&profile_prefs_);
+
+  // Generate views but not enough to reach the threshold.
+  const int notice_card_index = 0;
+  tracker.OnSliceViewed(notice_card_index);
+  tracker.OnSliceViewed(notice_card_index);
+
+  EXPECT_FALSE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest, DontAcknowledgedNoticeCardWhenFeatureDisabled) {
+  // Generate enough views and clicks on the notice card to reach the threshold,
+  // but the feature is disabled.
+  prefs::IncrementNoticeCardClicksCount(profile_prefs_);
+  prefs::IncrementNoticeCardViewsCount(profile_prefs_);
+  prefs::IncrementNoticeCardViewsCount(profile_prefs_);
+  prefs::IncrementNoticeCardViewsCount(profile_prefs_);
+
+  NoticeCardTracker tracker(&profile_prefs_);
+  EXPECT_FALSE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest,
+       DontAcknowledgedNoticeCardFromViewsCountWhenThresholdIsZero) {
+  base::FieldTrialParams params;
+  params[kNoticeCardViewsCountThresholdParamName] = "0";
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeatureWithParameters(
+      feed::kInterestFeedNoticeCardAutoDismiss, params);
+
+  NoticeCardTracker tracker(&profile_prefs_);
+  EXPECT_FALSE(tracker.HasAcknowledgedNoticeCard());
+}
+
+TEST_F(NoticeCardTrackerTest,
+       DontAcknowledgedNoticeCardFromClicksCountWhenThresholdIsZero) {
+  base::FieldTrialParams params;
+  params[kNoticeCardClicksCountThresholdParamName] = "0";
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeatureWithParameters(
+      feed::kInterestFeedNoticeCardAutoDismiss, params);
+
+  NoticeCardTracker tracker(&profile_prefs_);
+  EXPECT_FALSE(tracker.HasAcknowledgedNoticeCard());
+}
+
+}  // namespace
+}  // namespace feed
\ No newline at end of file
diff --git a/chromium/components/feed/core/v2/prefs.cc b/chromium/components/feed/core/v2/prefs.cc
index 562ff7d9c4f..49ef37fd3fe 100644
--- a/chromium/components/feed/core/v2/prefs.cc
+++ b/chromium/components/feed/core/v2/prefs.cc
@@ -106,6 +106,24 @@ bool GetHasReachedClickAndViewActionsUploadConditions(
       feed::prefs::kHasReachedClickAndViewActionsUploadConditions);
 }
 
+void IncrementNoticeCardViewsCount(PrefService& pref_service) {
+  int count = pref_service.GetInteger(feed::prefs::kNoticeCardViewsCount);
+  pref_service.SetInteger(feed::prefs::kNoticeCardViewsCount, count + 1);
+}
+
+int GetNoticeCardViewsCount(const PrefService& pref_service) {
+  return pref_service.GetInteger(feed::prefs::kNoticeCardViewsCount);
+}
+
+void IncrementNoticeCardClicksCount(PrefService& pref_service) {
+  int count = pref_service.GetInteger(feed::prefs::kNoticeCardClicksCount);
+  pref_service.SetInteger(feed::prefs::kNoticeCardClicksCount, count + 1);
+}
+
+int GetNoticeCardClicksCount(const PrefService& pref_service) {
+  return pref_service.GetInteger(feed::prefs::kNoticeCardClicksCount);
+}
+
 }  // namespace prefs
 
 }  // namespace feed
diff --git a/chromium/components/feed/core/v2/prefs.h b/chromium/components/feed/core/v2/prefs.h
index 634bddb16c6..e16befa3e47 100644
--- a/chromium/components/feed/core/v2/prefs.h
+++ b/chromium/components/feed/core/v2/prefs.h
@@ -52,6 +52,16 @@ void SetHasReachedClickAndViewActionsUploadConditions(PrefService& pref_service,
 bool GetHasReachedClickAndViewActionsUploadConditions(
     const PrefService& pref_service);
 
+// Increment the stored notice card views count by 1.
+void IncrementNoticeCardViewsCount(PrefService& pref_service);
+
+int GetNoticeCardViewsCount(const PrefService& pref_service);
+
+// Increment the stored notice card clicks count by 1.
+void IncrementNoticeCardClicksCount(PrefService& pref_service);
+
+int GetNoticeCardClicksCount(const PrefService& pref_service);
+
 }  // namespace prefs
 }  // namespace feed
 
diff --git a/chromium/components/feed/core/v2/proto_util.cc b/chromium/components/feed/core/v2/proto_util.cc
index aa21f4a1b93..d680ecfcf3f 100644
--- a/chromium/components/feed/core/v2/proto_util.cc
+++ b/chromium/components/feed/core/v2/proto_util.cc
@@ -13,10 +13,12 @@
 #include "build/build_config.h"
 #include "components/feed/core/proto/v2/store.pb.h"
 #include "components/feed/core/proto/v2/wire/capability.pb.h"
+#include "components/feed/core/proto/v2/wire/chrome_client_info.pb.h"
 #include "components/feed/core/proto/v2/wire/feed_request.pb.h"
 #include "components/feed/core/proto/v2/wire/request.pb.h"
 #include "components/feed/core/v2/config.h"
 #include "components/feed/core/v2/feed_stream.h"
+#include "components/feed/feed_feature_list.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/build_info.h"
@@ -124,9 +126,15 @@ feedwire::Request CreateFeedQueryRequest(
   *feed_request.mutable_client_info() = CreateClientInfo(request_metadata);
   feedwire::FeedQuery& query = *feed_request.mutable_feed_query();
   query.set_reason(request_reason);
-  if (!consistency_token.empty()) {
+
+  // |consistency_token|, for action reporting, is only applicable to signed-in
+  // requests. The presence of |client_instance_id|, also signed-in only, can be
+  // used a proxy for checking if we're creating a signed-in request.
+  if (!consistency_token.empty() &&
+      !request_metadata.client_instance_id.empty()) {
     feed_request.mutable_consistency_token()->set_token(consistency_token);
   }
+
   if (!next_page_token.empty()) {
     DCHECK_EQ(request_reason, feedwire::FeedQuery::NEXT_PAGE_SCROLL);
     query.mutable_next_page_token()
@@ -136,6 +144,16 @@ feedwire::Request CreateFeedQueryRequest(
   return request;
 }
 
+void SetNoticeCardAcknowledged(feedwire::Request* request,
+                               const RequestMetadata& request_metadata) {
+  if (request_metadata.notice_card_acknowledged) {
+    request->mutable_feed_request()
+        ->mutable_feed_query()
+        ->mutable_chrome_fulfillment_info()
+        ->set_notice_card_acknowledged(true);
+  }
+}
+
 }  // namespace
 
 std::string ContentIdString(const feedwire::ContentId& content_id) {
@@ -176,7 +194,6 @@ bool CompareContent(const feedstore::Content& a, const feedstore::Content& b) {
 
 feedwire::ClientInfo CreateClientInfo(const RequestMetadata& request_metadata) {
   feedwire::ClientInfo client_info;
-  client_info.set_client_instance_id(request_metadata.client_instance_id);
 
   feedwire::DisplayInfo& display_info = *client_info.add_display_info();
   display_info.set_screen_density(request_metadata.display_metrics.density);
@@ -196,6 +213,19 @@ feedwire::ClientInfo CreateClientInfo(const RequestMetadata& request_metadata) {
   *client_info.mutable_platform_version() = GetPlatformVersionMessage();
   *client_info.mutable_app_version() =
       GetAppVersionMessage(request_metadata.chrome_info);
+
+  // client_instance_id and session_id should not both be set at the same time.
+  DCHECK(request_metadata.client_instance_id.empty() ||
+         request_metadata.session_id.empty());
+
+  // Populate client_instance_id, session_id, or neither.
+  if (!request_metadata.client_instance_id.empty()) {
+    client_info.set_client_instance_id(request_metadata.client_instance_id);
+  } else if (!request_metadata.session_id.empty()) {
+    client_info.mutable_chrome_client_info()->set_session_id(
+        request_metadata.session_id);
+  }
+
   return client_info;
 }
 
@@ -203,8 +233,10 @@ feedwire::Request CreateFeedQueryRefreshRequest(
     feedwire::FeedQuery::RequestReason request_reason,
     const RequestMetadata& request_metadata,
     const std::string& consistency_token) {
-  return CreateFeedQueryRequest(request_reason, request_metadata,
-                                consistency_token, std::string());
+  feedwire::Request request = CreateFeedQueryRequest(
+      request_reason, request_metadata, consistency_token, std::string());
+  SetNoticeCardAcknowledged(&request, request_metadata);
+  return request;
 }
 
 feedwire::Request CreateFeedQueryLoadMoreRequest(
diff --git a/chromium/components/feed/core/v2/proto_util_unittest.cc b/chromium/components/feed/core/v2/proto_util_unittest.cc
index 53eecb56451..8d53ebe00fa 100644
--- a/chromium/components/feed/core/v2/proto_util_unittest.cc
+++ b/chromium/components/feed/core/v2/proto_util_unittest.cc
@@ -108,5 +108,31 @@ TEST(ProtoUtilTest, DisableCapabilitiesWithFinch) {
   EXPECT_TRUE(HasCapability(request, feedwire::Capability::PREFETCH_METADATA));
 }
 
+TEST(ProtoUtilTest, NoticeCardAcknowledged) {
+  RequestMetadata request_metadata;
+  request_metadata.notice_card_acknowledged = true;
+  feedwire::Request request = CreateFeedQueryRefreshRequest(
+      feedwire::FeedQuery::MANUAL_REFRESH, request_metadata,
+      /*consistency_token=*/std::string());
+
+  EXPECT_TRUE(request.feed_request()
+                  .feed_query()
+                  .chrome_fulfillment_info()
+                  .notice_card_acknowledged());
+}
+
+TEST(ProtoUtilTest, NoticeCardNotAcknowledged) {
+  RequestMetadata request_metadata;
+  request_metadata.notice_card_acknowledged = false;
+  feedwire::Request request = CreateFeedQueryRefreshRequest(
+      feedwire::FeedQuery::MANUAL_REFRESH, request_metadata,
+      /*consistency_token=*/std::string());
+
+  EXPECT_FALSE(request.feed_request()
+                   .feed_query()
+                   .chrome_fulfillment_info()
+                   .notice_card_acknowledged());
+}
+
 }  // namespace
 }  // namespace feed
diff --git a/chromium/components/feed/core/v2/protocol_translator.cc b/chromium/components/feed/core/v2/protocol_translator.cc
index db128746859..ea69442f531 100644
--- a/chromium/components/feed/core/v2/protocol_translator.cc
+++ b/chromium/components/feed/core/v2/protocol_translator.cc
@@ -306,6 +306,18 @@ RefreshResponseData TranslateWireResponse(
   result->stream_data.set_privacy_notice_fulfilled(
       response_metadata.privacy_notice_fulfilled());
 
+  base::Optional<std::string> session_id = base::nullopt;
+  if (was_signed_in_request) {
+    // Signed-in requests don't use session_id tokens; set an empty value to
+    // ensure that there are no old session_id tokens left hanging around.
+    session_id = std::string();
+  } else if (response_metadata.has_session_id()) {
+    // Signed-out requests can set a new session token; otherwise, we leave
+    // the default base::nullopt value to keep whatever token is already in
+    // play.
+    session_id = response_metadata.session_id();
+  }
+
   MetricsReporter::ActivityLoggingEnabled(response_metadata.logging_enabled());
   MetricsReporter::NoticeCardFulfilledObsolete(
       response_metadata.privacy_notice_fulfilled());
@@ -313,6 +325,7 @@ RefreshResponseData TranslateWireResponse(
   RefreshResponseData response_data;
   response_data.model_update_request = std::move(result);
   response_data.request_schedule = std::move(global_data.request_schedule);
+  response_data.session_id = std::move(session_id);
 
   return response_data;
 }
diff --git a/chromium/components/feed/core/v2/protocol_translator.h b/chromium/components/feed/core/v2/protocol_translator.h
index 3728e1e5dc4..b83a23fdecf 100644
--- a/chromium/components/feed/core/v2/protocol_translator.h
+++ b/chromium/components/feed/core/v2/protocol_translator.h
@@ -64,6 +64,9 @@ struct RefreshResponseData {
 
   // Server-defined request schedule, if provided.
   base::Optional<RequestSchedule> request_schedule;
+
+  // Server-defined session id token, if provided.
+  base::Optional<std::string> session_id;
 };
 
 base::Optional<feedstore::DataOperation> TranslateDataOperation(
diff --git a/chromium/components/feed/core/v2/public/feed_service.cc b/chromium/components/feed/core/v2/public/feed_service.cc
index 7e7a59776ee..b5836074240 100644
--- a/chromium/components/feed/core/v2/public/feed_service.cc
+++ b/chromium/components/feed/core/v2/public/feed_service.cc
@@ -121,6 +121,9 @@ class FeedService::StreamDelegateImpl : public FeedStream::Delegate {
     return service_delegate_->GetLanguageTag();
   }
   void ClearAll() override { service_delegate_->ClearAll(); }
+  void PrefetchImage(const GURL& url) override {
+    service_delegate_->PrefetchImage(url);
+  }
   bool IsSignedIn() override { return identity_manager_->HasPrimaryAccount(); }
 
  private:
diff --git a/chromium/components/feed/core/v2/public/feed_service.h b/chromium/components/feed/core/v2/public/feed_service.h
index ae3b5ddefb0..d8c1f2aa222 100644
--- a/chromium/components/feed/core/v2/public/feed_service.h
+++ b/chromium/components/feed/core/v2/public/feed_service.h
@@ -67,6 +67,8 @@ class FeedService : public KeyedService {
     virtual DisplayMetrics GetDisplayMetrics() = 0;
     // Clear all stored data.
     virtual void ClearAll() = 0;
+    // Fetch the image and store it in the disk cache.
+    virtual void PrefetchImage(const GURL& url) = 0;
   };
 
   // Construct a FeedService given an already constructed FeedStream.
diff --git a/chromium/components/feed/core/v2/public/feed_stream_api.h b/chromium/components/feed/core/v2/public/feed_stream_api.h
index d3bfabc34de..b33d9e87239 100644
--- a/chromium/components/feed/core/v2/public/feed_stream_api.h
+++ b/chromium/components/feed/core/v2/public/feed_stream_api.h
@@ -63,9 +63,14 @@ class FeedStreamApi {
   // as the feed is refreshed or the user signs in/out.
   virtual bool IsActivityLoggingEnabled() const = 0;
 
-  // Returns the client_instance_id. This value is reset whenever the feed
-  // stream is cleared (on sign-in, sign-out, and some data clear events).
-  virtual std::string GetClientInstanceId() = 0;
+  // Returns the signed-in client_instance_id. This value is reset whenever the
+  // feed stream is cleared (on sign-in, sign-out, and some data clear events).
+  virtual std::string GetClientInstanceId() const = 0;
+
+  // Returns the client's signed-out session id. This value is reset whenever
+  // the feed stream is cleared (on sign-in, sign-out, and some data clear
+  // events).
+  virtual std::string GetSessionId() const = 0;
 
   // Invoked by RefreshTaskScheduler's scheduled task.
   virtual void ExecuteRefreshTask() = 0;
@@ -170,6 +175,9 @@ class FeedStreamApi {
   virtual void ForceRefreshForDebugging() = 0;
   // Dumps some state information for debugging.
   virtual std::string DumpStateForDebugging() = 0;
+  // Forces to render a StreamUpdate on all subsequent surface attaches.
+  virtual void SetForcedStreamUpdateForDebugging(
+      const feedui::StreamUpdate& stream_update) = 0;
 };
 
 }  // namespace feed
diff --git a/chromium/components/feed/core/v2/public/types.h b/chromium/components/feed/core/v2/public/types.h
index 7680ef75813..0bdc72e7f07 100644
--- a/chromium/components/feed/core/v2/public/types.h
+++ b/chromium/components/feed/core/v2/public/types.h
@@ -48,6 +48,7 @@ struct NetworkResponseInfo {
   std::string bless_nonce;
   GURL base_request_url;
   size_t response_body_bytes = 0;
+  bool was_signed_in = false;
 };
 
 struct NetworkResponse {
diff --git a/chromium/components/feed/core/v2/tasks/load_more_task.cc b/chromium/components/feed/core/v2/tasks/load_more_task.cc
index 8c6dc6370aa..6afb90d4780 100644
--- a/chromium/components/feed/core/v2/tasks/load_more_task.cc
+++ b/chromium/components/feed/core/v2/tasks/load_more_task.cc
@@ -7,7 +7,7 @@
 #include <memory>
 #include <utility>
 
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/check.h"
 #include "base/time/clock.h"
 #include "base/time/tick_clock.h"
@@ -48,22 +48,34 @@ void LoadMoreTask::Run() {
 }
 
 void LoadMoreTask::UploadActionsComplete(UploadActionsTask::Result result) {
+  StreamModel* model = stream_->GetModel();
+  DCHECK(model) << "Model was unloaded outside of a Task";
+
+  // Determine whether the load more request should be forced signed-out
+  // regardless of the live sign-in state of the client.
+  //
+  // The signed-in state of the model is used instead of using
+  // FeedStream#ShouldForceSignedOutFeedQueryRequest because the load more
+  // requests should be in the same signed-in state as the prior requests that
+  // filled the model to have consistent data.
+  //
+  // The sign-in state of the load stream request that brings the initial
+  // content determines the sign-in state of the subsequent load more requests.
+  // This avoids a possible situation where there would be a mix of signed-in
+  // and signed-out content, which we don't want.
+  bool force_signed_out_request = !model->signed_in();
   // Send network request.
-  bool force_signed_out_request =
-      stream_->ShouldForceSignedOutFeedQueryRequest();
   fetch_start_time_ = stream_->GetTickClock()->NowTicks();
   stream_->GetNetwork()->SendQueryRequest(
       CreateFeedQueryLoadMoreRequest(
-          stream_->GetRequestMetadata(),
+          stream_->GetRequestMetadata(/*is_for_next_page=*/true),
           stream_->GetMetadata()->GetConsistencyToken(),
           stream_->GetModel()->GetNextPageToken()),
       force_signed_out_request,
-      base::BindOnce(&LoadMoreTask::QueryRequestComplete, GetWeakPtr(),
-                     force_signed_out_request));
+      base::BindOnce(&LoadMoreTask::QueryRequestComplete, GetWeakPtr()));
 }
 
 void LoadMoreTask::QueryRequestComplete(
-    bool was_forced_signed_out_request,
     FeedNetwork::QueryRequestResult result) {
   StreamModel* model = stream_->GetModel();
   DCHECK(model) << "Model was unloaded outside of a Task";
@@ -71,20 +83,21 @@ void LoadMoreTask::QueryRequestComplete(
   if (!result.response_body)
     return Done(LoadStreamStatus::kNoResponseBody);
 
-  bool was_signed_in_request =
-      !was_forced_signed_out_request && stream_->IsSignedIn();
-
   RefreshResponseData translated_response =
       stream_->GetWireResponseTranslator()->TranslateWireResponse(
           *result.response_body,
           StreamModelUpdateRequest::Source::kNetworkLoadMore,
-          was_signed_in_request, stream_->GetClock()->Now());
+          result.response_info.was_signed_in, stream_->GetClock()->Now());
 
   if (!translated_response.model_update_request)
     return Done(LoadStreamStatus::kProtoTranslationFailed);
 
   loaded_new_content_from_network_ =
       !translated_response.model_update_request->stream_structures.empty();
+
+  stream_->GetMetadata()->MaybeUpdateSessionId(translated_response.session_id,
+                                               stream_->GetClock());
+
   model->Update(std::move(translated_response.model_update_request));
 
   if (translated_response.request_schedule)
diff --git a/chromium/components/feed/core/v2/tasks/load_more_task.h b/chromium/components/feed/core/v2/tasks/load_more_task.h
index 397c4eb1cab..538fcf9c75d 100644
--- a/chromium/components/feed/core/v2/tasks/load_more_task.h
+++ b/chromium/components/feed/core/v2/tasks/load_more_task.h
@@ -44,8 +44,7 @@ class LoadMoreTask : public offline_pages::Task {
   }
 
   void UploadActionsComplete(UploadActionsTask::Result result);
-  void QueryRequestComplete(bool was_signed_in_request,
-                            FeedNetwork::QueryRequestResult result);
+  void QueryRequestComplete(FeedNetwork::QueryRequestResult result);
   void Done(LoadStreamStatus status);
 
   FeedStream* stream_;  // Unowned.
diff --git a/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.cc b/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.cc
index 71fff522a38..999d5f6fae9 100644
--- a/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.cc
+++ b/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.cc
@@ -126,8 +126,6 @@ void LoadStreamFromStoreTask::Complete(LoadStreamStatus status) {
   if (status == LoadStreamStatus::kLoadedFromStore &&
       load_type_ == LoadType::kFullLoad) {
     task_result.update_request = std::move(update_request_);
-  } else {
-    task_result.consistency_token = consistency_token_;
   }
   std::move(result_callback_).Run(std::move(task_result));
   TaskComplete();
diff --git a/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.h b/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.h
index 61dee09d676..fef672dc9ac 100644
--- a/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.h
+++ b/chromium/components/feed/core/v2/tasks/load_stream_from_store_task.h
@@ -76,7 +76,6 @@ class LoadStreamFromStoreTask : public offline_pages::Task {
 
   // Data to be stuffed into the Result when the task is complete.
   std::unique_ptr<StreamModelUpdateRequest> update_request_;
-  std::string consistency_token_;
   std::vector<feedstore::StoredAction> pending_actions_;
 
   base::WeakPtrFactory<LoadStreamFromStoreTask> weak_ptr_factory_{this};
diff --git a/chromium/components/feed/core/v2/tasks/load_stream_task.cc b/chromium/components/feed/core/v2/tasks/load_stream_task.cc
index c061f9d91bf..9b4f04b1e69 100644
--- a/chromium/components/feed/core/v2/tasks/load_stream_task.cc
+++ b/chromium/components/feed/core/v2/tasks/load_stream_task.cc
@@ -7,7 +7,7 @@
 #include <memory>
 #include <utility>
 
-#include "base/bind_helpers.h"
+#include "base/callback_helpers.h"
 #include "base/check.h"
 #include "base/time/clock.h"
 #include "base/time/tick_clock.h"
@@ -123,15 +123,14 @@ void LoadStreamTask::UploadActionsComplete(UploadActionsTask::Result result) {
   latencies_->StepComplete(LoadLatencyTimes::kUploadActions);
   stream_->GetNetwork()->SendQueryRequest(
       CreateFeedQueryRefreshRequest(
-          GetRequestReason(load_type_), stream_->GetRequestMetadata(),
+          GetRequestReason(load_type_),
+          stream_->GetRequestMetadata(/*is_for_next_page=*/false),
           stream_->GetMetadata()->GetConsistencyToken()),
       force_signed_out_request,
-      base::BindOnce(&LoadStreamTask::QueryRequestComplete, GetWeakPtr(),
-                     force_signed_out_request));
+      base::BindOnce(&LoadStreamTask::QueryRequestComplete, GetWeakPtr()));
 }
 
 void LoadStreamTask::QueryRequestComplete(
-    bool was_forced_signed_out_request,
     FeedNetwork::QueryRequestResult result) {
   latencies_->StepComplete(LoadLatencyTimes::kQueryRequest);
 
@@ -149,14 +148,11 @@ void LoadStreamTask::QueryRequestComplete(
       return Done(LoadStreamStatus::kNoResponseBody);
   }
 
-  bool was_signed_in_request =
-      !was_forced_signed_out_request && stream_->IsSignedIn();
-
   RefreshResponseData response_data =
       stream_->GetWireResponseTranslator()->TranslateWireResponse(
           *result.response_body,
           StreamModelUpdateRequest::Source::kNetworkUpdate,
-          was_signed_in_request, stream_->GetClock()->Now());
+          result.response_info.was_signed_in, stream_->GetClock()->Now());
   if (!response_data.model_update_request)
     return Done(LoadStreamStatus::kProtoTranslationFailed);
 
@@ -172,6 +168,9 @@ void LoadStreamTask::QueryRequestComplete(
   stream_->SetLastStreamLoadHadNoticeCard(isNoticeCardFulfilled);
   MetricsReporter::NoticeCardFulfilled(isNoticeCardFulfilled);
 
+  stream_->GetMetadata()->MaybeUpdateSessionId(response_data.session_id,
+                                               stream_->GetClock());
+
   if (load_type_ != LoadType::kBackgroundRefresh) {
     auto model = std::make_unique<StreamModel>();
     model->Update(std::move(response_data.model_update_request));
diff --git a/chromium/components/feed/core/v2/tasks/load_stream_task.h b/chromium/components/feed/core/v2/tasks/load_stream_task.h
index 6e8993959ac..dd4c210db73 100644
--- a/chromium/components/feed/core/v2/tasks/load_stream_task.h
+++ b/chromium/components/feed/core/v2/tasks/load_stream_task.h
@@ -74,8 +74,7 @@ class LoadStreamTask : public offline_pages::Task {
 
   void LoadFromStoreComplete(LoadStreamFromStoreTask::Result result);
   void UploadActionsComplete(UploadActionsTask::Result result);
-  void QueryRequestComplete(bool was_signed_in_request,
-                            FeedNetwork::QueryRequestResult result);
+  void QueryRequestComplete(FeedNetwork::QueryRequestResult result);
   void Done(LoadStreamStatus status);
 
   LoadType load_type_;
diff --git a/chromium/components/feed/core/v2/tasks/prefetch_images_task.cc b/chromium/components/feed/core/v2/tasks/prefetch_images_task.cc
new file mode 100644
index 00000000000..f8a927ba6af
--- /dev/null
+++ b/chromium/components/feed/core/v2/tasks/prefetch_images_task.cc
@@ -0,0 +1,100 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/feed/core/v2/tasks/prefetch_images_task.h"
+
+#include <utility>
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "components/feed/core/proto/v2/wire/stream_structure.pb.h"
+#include "components/feed/core/v2/config.h"
+#include "components/feed/core/v2/feed_store.h"
+#include "components/feed/core/v2/feed_stream.h"
+#include "components/feed/core/v2/stream_model.h"
+#include "components/feed/core/v2/tasks/load_stream_from_store_task.h"
+
+namespace feed {
+namespace {
+
+// Converts a URL string into a GURL. If the string is not a valid URL, returns
+// an empty GURL. Since GURL::spec() asserts on invalid URLs, this is necessary
+// to scrub the incoming data from the wire.
+GURL SpecToGURL(const std::string& url_string) {
+  GURL url(url_string);
+  if (!url.is_valid())
+    url = GURL();
+  return url;
+}
+
+}  // namespace
+
+PrefetchImagesTask::PrefetchImagesTask(FeedStream* stream) : stream_(stream) {
+  max_images_per_refresh_ =
+      GetFeedConfig().max_prefetch_image_requests_per_refresh;
+}
+
+PrefetchImagesTask::~PrefetchImagesTask() = default;
+
+void PrefetchImagesTask::Run() {
+  if (stream_->GetModel()) {
+    PrefetchImagesFromModel(*stream_->GetModel());
+    return;
+  }
+
+  load_from_store_task_ = std::make_unique<LoadStreamFromStoreTask>(
+      LoadStreamFromStoreTask::LoadType::kFullLoad, stream_->GetStore(),
+      stream_->GetClock(),
+      base::BindOnce(&PrefetchImagesTask::LoadStreamComplete,
+                     base::Unretained(this)));
+
+  load_from_store_task_->Execute(base::DoNothing());
+}
+
+void PrefetchImagesTask::LoadStreamComplete(
+    LoadStreamFromStoreTask::Result result) {
+  if (!result.update_request) {
+    TaskComplete();
+    return;
+  }
+
+  // It is a bit dangerous to retain the model loaded here. The normal
+  // LoadStreamTask flow has various considerations for metrics and signalling
+  // surfaces to update. For this reason, we're not going to retain the loaded
+  // model for use outside of this task.
+  StreamModel model;
+  model.Update(std::move(result.update_request));
+  PrefetchImagesFromModel(model);
+}
+
+void PrefetchImagesTask::PrefetchImagesFromModel(const StreamModel& model) {
+  for (ContentRevision rev : model.GetContentList()) {
+    const feedstore::Content* content = model.FindContent(rev);
+    if (!content)
+      continue;
+    for (const feedwire::PrefetchMetadata& metadata :
+         content->prefetch_metadata()) {
+      MaybePrefetchImage(SpecToGURL(metadata.image_url()));
+      MaybePrefetchImage(SpecToGURL(metadata.favicon_url()));
+      for (const std::string& url : metadata.additional_image_urls()) {
+        MaybePrefetchImage(SpecToGURL(url));
+      }
+    }
+  }
+
+  TaskComplete();
+}
+
+void PrefetchImagesTask::MaybePrefetchImage(const GURL& gurl) {
+  // If we've already fetched this url, or we've hit the max number of fetches,
+  // then don't send a fetch request.
+  if (!gurl.is_valid() ||
+      (previously_fetched_.find(gurl.spec()) != previously_fetched_.end()) ||
+      previously_fetched_.size() >= max_images_per_refresh_)
+    return;
+  previously_fetched_.insert(gurl.spec());
+  stream_->PrefetchImage(gurl);
+}
+
+}  // namespace feed
diff --git a/chromium/components/feed/core/v2/tasks/prefetch_images_task.h b/chromium/components/feed/core/v2/tasks/prefetch_images_task.h
new file mode 100644
index 00000000000..ddc24a6cc76
--- /dev/null
+++ b/chromium/components/feed/core/v2/tasks/prefetch_images_task.h
@@ -0,0 +1,51 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_FEED_CORE_V2_TASKS_PREFETCH_IMAGES_TASK_H_
+#define COMPONENTS_FEED_CORE_V2_TASKS_PREFETCH_IMAGES_TASK_H_
+
+#include <memory>
+#include <vector>
+
+#include "base/memory/weak_ptr.h"
+#include "components/feed/core/v2/tasks/load_stream_from_store_task.h"
+#include "components/offline_pages/task/task.h"
+
+namespace feed {
+class FeedStream;
+class StreamModel;
+
+// Prefetch the images in the model.
+class PrefetchImagesTask : public offline_pages::Task {
+ public:
+  explicit PrefetchImagesTask(FeedStream* stream);
+  ~PrefetchImagesTask() override;
+  PrefetchImagesTask(const PrefetchImagesTask&) = delete;
+  PrefetchImagesTask& operator=(const PrefetchImagesTask&) = delete;
+
+ private:
+  base::WeakPtr<PrefetchImagesTask> GetWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
+  // offline_pages::Task.
+  void Run() override;
+
+  void LoadStreamComplete(LoadStreamFromStoreTask::Result result);
+
+  void PrefetchImagesFromModel(const StreamModel& model);
+
+  void MaybePrefetchImage(const GURL& gurl);
+
+  FeedStream* stream_;
+  std::unordered_set<std::string> previously_fetched_;
+  unsigned long max_images_per_refresh_;
+
+  std::unique_ptr<LoadStreamFromStoreTask> load_from_store_task_;
+
+  base::WeakPtrFactory<PrefetchImagesTask> weak_ptr_factory_{this};
+};
+}  // namespace feed
+
+#endif  // COMPONENTS_FEED_CORE_V2_TASKS_PREFETCH_IMAGES_TASK_H_
diff --git a/chromium/components/feed/core/v2/types.h b/chromium/components/feed/core/v2/types.h
index 883effa2bfb..508e56c98e4 100644
--- a/chromium/components/feed/core/v2/types.h
+++ b/chromium/components/feed/core/v2/types.h
@@ -39,7 +39,9 @@ struct RequestMetadata {
   ChromeInfo chrome_info;
   std::string language_tag;
   std::string client_instance_id;
+  std::string session_id;
   DisplayMetrics display_metrics;
+  bool notice_card_acknowledged = false;
 };
 
 // Data internal to MetricsReporter which is persisted to Prefs.
diff --git a/chromium/components/feed/features.gni b/chromium/components/feed/features.gni
index 022f876896e..627f7d7bf52 100644
--- a/chromium/components/feed/features.gni
+++ b/chromium/components/feed/features.gni
@@ -2,12 +2,28 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//chrome/android/channel.gni")
+
 # Chrome can be built with any combination of v1/v2 enabled.
 # When both are enabled, we use the InterestFeedV2 feature to select which
 # one is used at runtime.
 # If both are false, some of the Feed V2 UI classes are still used to display
 # the NTP.
 declare_args() {
+  # Whether version 1 of the NTP feed is enabled in the build.
   enable_feed_v1 = is_android
+
+  # Whether version 2 of the NTP feed is enabled in the build.
   enable_feed_v2 = is_android
+
+  # Whether to include Feed V2 in ChromeModern builds.
+  enable_feed_v2_modern = true
+
+  # Whether to include Feed V2 as a DFM in ChromeModern builds.
+  dfmify_feed_v2_modern = false
+}
+
+if (is_android && android_channel != "default") {
+  # You probably don't want to build without either version in a Clank release.
+  assert(enable_feed_v1 || enable_feed_v2)
 }
diff --git a/chromium/components/feed/feed_feature_list.cc b/chromium/components/feed/feed_feature_list.cc
index 8065e083e04..f9cf11aba5e 100644
--- a/chromium/components/feed/feed_feature_list.cc
+++ b/chromium/components/feed/feed_feature_list.cc
@@ -30,9 +30,6 @@ const base::FeatureParam<bool> kOnlySetLastRefreshAttemptOnSuccess{
     &kInterestFeedContentSuggestions,
     "only_set_last_refresh_attempt_on_success", true};
 
-const base::Feature kInterestFeedFeedback{"InterestFeedFeedback",
-                                          base::FEATURE_DISABLED_BY_DEFAULT};
-
 const base::Feature kReportFeedUserActions{"ReportFeedUserActions",
                                            base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -47,6 +44,15 @@ const base::Feature kInterestFeedV2ClicksAndViewsConditionalUpload{
     "InterestFeedV2ClickAndViewActionsConditionalUpload",
     base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Feature that allows the client to automatically dismiss the notice card based
+// on the clicks and views on the notice card.
+const base::Feature kInterestFeedNoticeCardAutoDismiss{
+    "InterestFeedNoticeCardAutoDismiss", base::FEATURE_DISABLED_BY_DEFAULT};
+
+// Used for A:B testing of a bug fix (crbug.com/1151391).
+const base::Feature kInterestFeedSpinnerAlwaysAnimate{
+    "InterestFeedSpinnerAlwaysAnimate", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const char kDefaultReferrerUrl[] =
     "https://www.googleapis.com/auth/chrome-content-suggestions";
 
diff --git a/chromium/components/feed/feed_feature_list.h b/chromium/components/feed/feed_feature_list.h
index 3fd0e3cb300..432ba988ff8 100644
--- a/chromium/components/feed/feed_feature_list.h
+++ b/chromium/components/feed/feed_feature_list.h
@@ -24,8 +24,6 @@ extern const base::FeatureParam<int> kTimeoutDurationSeconds;
 extern const base::FeatureParam<bool> kThrottleBackgroundFetches;
 extern const base::FeatureParam<bool> kOnlySetLastRefreshAttemptOnSuccess;
 
-extern const base::Feature kInterestFeedFeedback;
-
 // Indicates if user card clicks and views in Chrome's feed should be reported
 // for personalization. Also enables the feed header menu to manage the feed.
 extern const base::Feature kReportFeedUserActions;
@@ -33,6 +31,10 @@ extern const base::Feature kReportFeedUserActions;
 extern const base::Feature kInterestFeedV1ClicksAndViewsConditionalUpload;
 extern const base::Feature kInterestFeedV2ClicksAndViewsConditionalUpload;
 
+extern const base::Feature kInterestFeedNoticeCardAutoDismiss;
+
+extern const base::Feature kInterestFeedSpinnerAlwaysAnimate;
+
 std::string GetFeedReferrerUrl();
 
 }  // namespace feed