[core] split backend from mapobserver

15 files changed, 81 insertions, 83 deletions

diff --git a/benchmark/api/query.benchmark.cpp b/benchmark/api/query.benchmark.cpp
index 4c11a56da5..b88ecb7749 100644
--- a/benchmark/api/query.benchmark.cpp
+++ b/benchmark/api/query.benchmark.cpp
@@ -38,7 +38,7 @@ public:
     OffscreenView view{ backend.getContext(), { 1000, 1000 } };
     DefaultFileSource fileSource{ "benchmark/fixtures/api/cache.db", "." };
     ThreadPool threadPool{ 4 };
-    Map map{ backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still };
+    Map map{ backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still };
     ScreenBox box{{ 0, 0 }, { 1000, 1000 }};
 };
 
diff --git a/benchmark/api/render.benchmark.cpp b/benchmark/api/render.benchmark.cpp
index 8c71c1a9bf..aea2af745a 100644
--- a/benchmark/api/render.benchmark.cpp
+++ b/benchmark/api/render.benchmark.cpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/benchmark/util.hpp>
 #include <mbgl/map/map.hpp>
+#include <mbgl/map/map_observer.hpp>
 #include <mbgl/map/backend_scope.hpp>
 #include <mbgl/gl/headless_backend.hpp>
 #include <mbgl/gl/offscreen_view.hpp>
@@ -44,7 +45,7 @@ static void prepare(Map& map, optional<std::string> json = {}) {
 
 static void API_renderStill_reuse_map(::benchmark::State& state) {
     RenderBenchmark bench;
-    Map map { bench.backend, bench.view.getSize(), 1, bench.fileSource, bench.threadPool, MapMode::Still };
+    Map map { bench.backend, MapObserver::nullObserver(), bench.view.getSize(), 1, bench.fileSource, bench.threadPool, MapMode::Still };
     prepare(map);
 
     while (state.KeepRunning()) {
@@ -54,7 +55,7 @@ static void API_renderStill_reuse_map(::benchmark::State& state) {
 
 static void API_renderStill_reuse_map_switch_styles(::benchmark::State& state) {
     RenderBenchmark bench;
-    Map map { bench.backend, bench.view.getSize(), 1, bench.fileSource, bench.threadPool, MapMode::Still };
+    Map map { bench.backend, MapObserver::nullObserver(), bench.view.getSize(), 1, bench.fileSource, bench.threadPool, MapMode::Still };
     
     while (state.KeepRunning()) {
         prepare(map, { "{}" });
@@ -68,7 +69,7 @@ static void API_renderStill_recreate_map(::benchmark::State& state) {
     RenderBenchmark bench;
     
     while (state.KeepRunning()) {
-        Map map { bench.backend, bench.view.getSize(), 1, bench.fileSource, bench.threadPool, MapMode::Still };
+        Map map { bench.backend, MapObserver::nullObserver(), bench.view.getSize(), 1, bench.fileSource, bench.threadPool, MapMode::Still };
         prepare(map);
         mbgl::benchmark::render(map, bench.view);
     }
diff --git a/bin/render.cpp b/bin/render.cpp
index 51c6faef56..74fd6fdcc4 100644
--- a/bin/render.cpp
+++ b/bin/render.cpp
@@ -88,7 +88,7 @@ int main(int argc, char *argv[]) {
     OffscreenView view(backend.getContext(), { static_cast<uint32_t>(width * pixelRatio),
                                                static_cast<uint32_t>(height * pixelRatio) });
     ThreadPool threadPool(4);
-    Map map(backend, mbgl::Size { width, height }, pixelRatio, fileSource, threadPool, MapMode::Still);
+    Map map(backend, MapObserver::nullObserver(), mbgl::Size { width, height }, pixelRatio, fileSource, threadPool, MapMode::Still);
 
     if (style_path.find("://") == std::string::npos) {
         style_path = std::string("file://") + style_path;
diff --git a/include/mbgl/map/backend.hpp b/include/mbgl/map/backend.hpp
index 2e73ad994c..434f68779c 100644
--- a/include/mbgl/map/backend.hpp
+++ b/include/mbgl/map/backend.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <mbgl/map/map_observer.hpp>
+#include <mbgl/map/view.hpp>
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/size.hpp>
 
@@ -17,7 +17,7 @@ using FramebufferID = uint32_t;
 
 class BackendScope;
 
-class Backend : public MapObserver {
+class Backend {
 public:
     Backend();
     virtual ~Backend();
diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index d82a260362..22ac100c40 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -33,6 +33,7 @@ class Style;
 class Map : private util::noncopyable {
 public:
     explicit Map(Backend&,
+                 MapObserver&,
                  Size size,
                  float pixelRatio,
                  FileSource&,
diff --git a/src/mbgl/map/map.cpp b/src/mbgl/map/map.cpp
index e644f91c4f..172b2bf851 100644
--- a/src/mbgl/map/map.cpp
+++ b/src/mbgl/map/map.cpp
@@ -49,6 +49,7 @@ class Map::Impl : public style::Observer,
 public:
     Impl(Map&,
          Backend&,
+         MapObserver&,
          float pixelRatio,
          FileSource&,
          Scheduler&,
@@ -104,6 +105,7 @@ public:
 };
 
 Map::Map(Backend& backend,
+         MapObserver& mapObserver,
          const Size size,
          const float pixelRatio,
          FileSource& fileSource,
@@ -115,6 +117,7 @@ Map::Map(Backend& backend,
          optional<std::string> programCacheDir)
     : impl(std::make_unique<Impl>(*this,
                                   backend,
+                                  mapObserver,
                                   pixelRatio,
                                   fileSource,
                                   scheduler,
@@ -128,6 +131,7 @@ Map::Map(Backend& backend,
 
 Map::Impl::Impl(Map& map_,
                 Backend& backend_,
+                MapObserver& mapObserver,
                 float pixelRatio_,
                 FileSource& fileSource_,
                 Scheduler& scheduler_,
@@ -137,7 +141,7 @@ Map::Impl::Impl(Map& map_,
                 ViewportMode viewportMode_,
                 optional<std::string> programCacheDir_)
     : map(map_),
-      observer(backend_),
+      observer(mapObserver),
       backend(backend_),
       fileSource(fileSource_),
       scheduler(scheduler_),
diff --git a/test/api/annotations.test.cpp b/test/api/annotations.test.cpp
index 7594d5ed73..42fbcc0a8b 100644
--- a/test/api/annotations.test.cpp
+++ b/test/api/annotations.test.cpp
@@ -33,7 +33,7 @@ public:
     OffscreenView view { backend.getContext() };
     StubFileSource fileSource;
     ThreadPool threadPool { 4 };
-    Map map { backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still };
+    Map map { backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still };
 
     void checkRendering(const char * name) {
         test::checkImage(std::string("test/fixtures/annotations/") + name,
diff --git a/test/api/api_misuse.test.cpp b/test/api/api_misuse.test.cpp
index 54cde8d9b5..e5498576a8 100644
--- a/test/api/api_misuse.test.cpp
+++ b/test/api/api_misuse.test.cpp
@@ -29,7 +29,7 @@ TEST(API, RenderWithoutCallback) {
     ThreadPool threadPool(4);
 
     std::unique_ptr<Map> map =
-        std::make_unique<Map>(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still);
+        std::make_unique<Map>(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still);
     map->renderStill(view, nullptr);
 
     // Force Map thread to join.
diff --git a/test/api/custom_layer.test.cpp b/test/api/custom_layer.test.cpp
index 2b1138a1d3..b5d94f2786 100644
--- a/test/api/custom_layer.test.cpp
+++ b/test/api/custom_layer.test.cpp
@@ -93,7 +93,7 @@ TEST(CustomLayer, Basic) {
     DefaultFileSource fileSource(":memory:", "test/fixtures/api/assets");
     ThreadPool threadPool(4);
 
-    Map map(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still);
+    Map map(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still);
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
     map.setLatLngZoom({ 37.8, -122.5 }, 10);
     map.getStyle().addLayer(std::make_unique<CustomLayer>(
diff --git a/test/api/query.test.cpp b/test/api/query.test.cpp
index 0b6d75ec4f..0b02e47219 100644
--- a/test/api/query.test.cpp
+++ b/test/api/query.test.cpp
@@ -33,7 +33,7 @@ public:
     OffscreenView view { backend.getContext() };
     StubFileSource fileSource;
     ThreadPool threadPool { 4 };
-    Map map { backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still };
+    Map map { backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still };
 };
 
 } // end namespace
diff --git a/test/api/render_missing.test.cpp b/test/api/render_missing.test.cpp
index 2e0c4401f4..9cba1dcac7 100644
--- a/test/api/render_missing.test.cpp
+++ b/test/api/render_missing.test.cpp
@@ -35,7 +35,7 @@ TEST(API, TEST_REQUIRES_SERVER(RenderMissingTile)) {
 
     Log::setObserver(std::make_unique<FixtureLogObserver>());
 
-    Map map(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still);
+    Map map(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still);
 
     std::string message;
 
diff --git a/test/api/repeated_render.test.cpp b/test/api/repeated_render.test.cpp
index dd9085efd7..033b741ab6 100644
--- a/test/api/repeated_render.test.cpp
+++ b/test/api/repeated_render.test.cpp
@@ -33,7 +33,7 @@ TEST(API, RepeatedRender) {
 
     Log::setObserver(std::make_unique<FixtureLogObserver>());
 
-    Map map(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still);
+    Map map(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still);
 
     {
         map.getStyle().loadJSON(style);
@@ -86,7 +86,7 @@ TEST(API, ZoomHistory) {
 
     Log::setObserver(std::make_unique<FixtureLogObserver>());
 
-    Map map(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still);
+    Map map(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still);
     map.getStyle().loadJSON(style);
 
     auto geojson = mapbox::geojson::parse(R"t({ "type": "FeatureCollection", "features": [{ "type": "Feature", "properties": {}, "geometry": { "type": "LineString", "coordinates": [ [ -150, -75 ], [  150,  75 ] ] } } ] })t");
diff --git a/test/map/map.test.cpp b/test/map/map.test.cpp
index a820590fb4..206371613d 100644
--- a/test/map/map.test.cpp
+++ b/test/map/map.test.cpp
@@ -25,42 +25,46 @@ using namespace mbgl;
 using namespace mbgl::style;
 using namespace std::literals::string_literals;
 
-class BackendTest : public HeadlessBackend {
+class MockBackend : public HeadlessBackend {
 public:
-    BackendTest() : HeadlessBackend(test::sharedDisplay()) {}
+    MockBackend()
+            : HeadlessBackend(test::sharedDisplay() ) {
+    }
 
-    void invalidate() {
-        if (invalidateCallback) {
-            invalidateCallback();
+    std::function<void()> callback;
+    void invalidate() override {
+        if (callback) {
+            callback();
         }
     }
+};
 
-    std::function<void()> invalidateCallback;
-
+class StubMapObserver : public MapObserver {
+public:
     void onWillStartLoadingMap() final {
         if (onWillStartLoadingMapCallback) {
             onWillStartLoadingMapCallback();
         }
     }
-
+    
     void onDidFinishLoadingMap() final {
         if (onDidFinishLoadingMapCallback) {
             onDidFinishLoadingMapCallback();
         }
     }
-
+    
     void onDidFailLoadingMap(std::exception_ptr) final {
         if (didFailLoadingMapCallback) {
             didFailLoadingMapCallback();
         }
     }
-
+    
     void onDidFinishLoadingStyle() final {
         if (didFinishLoadingStyleCallback) {
             didFinishLoadingStyleCallback();
         }
     }
-
+    
     std::function<void()> onWillStartLoadingMapCallback;
     std::function<void()> onDidFinishLoadingMapCallback;
     std::function<void()> didFailLoadingMapCallback;
@@ -69,7 +73,8 @@ public:
 
 struct MapTest {
     util::RunLoop runLoop;
-    BackendTest backend;
+    MockBackend backend;
+    StubMapObserver observer;
     BackendScope scope { backend };
     OffscreenView view { backend.getContext() };
     StubFileSource fileSource;
@@ -78,7 +83,7 @@ struct MapTest {
 
 TEST(Map, LatLngBehavior) {
     MapTest test;
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
 
     map.setLatLngZoom({ 1, 1 }, 0);
     auto latLng1 = map.getLatLng();
@@ -92,7 +97,7 @@ TEST(Map, LatLngBehavior) {
 
 TEST(Map, LatLngBoundsToCamera) {
     MapTest test;
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
 
     map.setLatLngZoom({ 40.712730, -74.005953 }, 16.0);
 
@@ -104,7 +109,7 @@ TEST(Map, LatLngBoundsToCamera) {
 
 TEST(Map, CameraToLatLngBounds) {
     MapTest test;
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
 
     map.setLatLngZoom({ 45, 90 }, 16);
 
@@ -143,7 +148,7 @@ TEST(Map, Offline) {
     fileSource.put(Resource::glyphs(prefix + "{fontstack}/{range}.pbf", {{"Helvetica"}}, {0, 255}), expiredItem("glyph.pbf"));
     NetworkStatus::Set(NetworkStatus::Status::Offline);
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL(prefix + "style.json");
 
     test::checkImage("test/fixtures/map/offline",
@@ -160,12 +165,12 @@ TEST(Map, SetStyleInvalidJSON) {
     Log::setObserver(std::make_unique<FixtureLogObserver>());
 
     bool fail = false;
-    test.backend.didFailLoadingMapCallback = [&]() {
+    test.observer.didFailLoadingMapCallback = [&]() {
         fail = true;
     };
 
     {
-        Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool,
+        Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool,
                 MapMode::Still);
         map.getStyle().loadJSON("invalid");
     }
@@ -191,11 +196,11 @@ TEST(Map, SetStyleInvalidURL) {
         return response;
     };
 
-    test.backend.didFailLoadingMapCallback = [&]() {
+    test.observer.didFailLoadingMapCallback = [&]() {
         test.runLoop.stop();
     };
 
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://bar");
 
     test.runLoop.run();
@@ -204,7 +209,7 @@ TEST(Map, SetStyleInvalidURL) {
 TEST(Map, DoubleStyleLoad) {
     MapTest test;
 
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadJSON("");
     map.getStyle().loadJSON("");
 }
@@ -215,7 +220,7 @@ TEST(Map, StyleFresh) {
     MapTest test;
     FakeFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://styles/test");
     EXPECT_EQ(1u, fileSource.requests.size());
 
@@ -235,7 +240,7 @@ TEST(Map, StyleExpired) {
     MapTest test;
     FakeFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://styles/test");
     EXPECT_EQ(1u, fileSource.requests.size());
 
@@ -262,7 +267,7 @@ TEST(Map, StyleExpiredWithAnnotations) {
     MapTest test;
     FakeFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://styles/test");
     EXPECT_EQ(1u, fileSource.requests.size());
 
@@ -288,7 +293,7 @@ TEST(Map, StyleExpiredWithRender) {
     MapTest test;
     FakeFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://styles/test");
     EXPECT_EQ(1u, fileSource.requests.size());
 
@@ -312,7 +317,7 @@ TEST(Map, StyleEarlyMutation) {
     MapTest test;
     FakeFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://styles/test");
     map.getStyle().addLayer(std::make_unique<style::BackgroundLayer>("bg"));
 
@@ -326,10 +331,10 @@ TEST(Map, StyleEarlyMutation) {
 
 TEST(Map, MapLoadingSignal) {
     MapTest test;
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
 
     bool emitted = false;
-    test.backend.onWillStartLoadingMapCallback = [&]() {
+    test.observer.onWillStartLoadingMapCallback = [&]() {
         emitted = true;
     };
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/empty.json"));
@@ -338,13 +343,13 @@ TEST(Map, MapLoadingSignal) {
 
 TEST(Map, MapLoadedSignal) {
     MapTest test;
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Continuous);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Continuous);
 
-    test.backend.onDidFinishLoadingMapCallback = [&]() {
+    test.observer.onDidFinishLoadingMapCallback = [&]() {
         test.runLoop.stop();
     };
 
-    test.backend.invalidateCallback = [&]() {
+    test.backend.callback = [&]() {
         map.render(test.view);
     };
 
@@ -354,11 +359,11 @@ TEST(Map, MapLoadedSignal) {
 
 TEST(Map, StyleLoadedSignal) {
     MapTest test;
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
 
     // The map should emit a signal on style loaded
     bool emitted = false;
-    test.backend.didFinishLoadingStyleCallback = [&]() {
+    test.observer.didFinishLoadingStyleCallback = [&]() {
         emitted = true;
     };
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/empty.json"));
@@ -375,10 +380,10 @@ TEST(Map, TEST_REQUIRES_SERVER(StyleNetworkErrorRetry)) {
     MapTest test;
     OnlineFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("http://127.0.0.1:3000/style-fail-once-500");
 
-    test.backend.didFinishLoadingStyleCallback = [&]() {
+    test.observer.didFinishLoadingStyleCallback = [&]() {
         test.runLoop.stop();
     };
 
@@ -389,18 +394,18 @@ TEST(Map, TEST_REQUIRES_SERVER(StyleNotFound)) {
     MapTest test;
     OnlineFileSource fileSource;
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("http://127.0.0.1:3000/style-fail-once-404");
 
     using namespace std::chrono_literals;
     util::Timer timer;
 
     // Not found errors should not trigger a retry like other errors.
-    test.backend.didFinishLoadingStyleCallback = [&]() {
+    test.observer.didFinishLoadingStyleCallback = [&]() {
         FAIL() << "Should not retry on not found!";
     };
 
-    test.backend.didFailLoadingMapCallback = [&]() {
+    test.observer.didFailLoadingMapCallback = [&]() {
         timer.start(Milliseconds(1100), 0s, [&] {
             test.runLoop.stop();
         });
@@ -416,7 +421,7 @@ TEST(Map, TEST_REQUIRES_SERVER(StyleNotFound)) {
 TEST(Map, AddLayer) {
     MapTest test;
 
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/empty.json"));
 
     auto layer = std::make_unique<BackgroundLayer>("background");
@@ -433,7 +438,7 @@ TEST(Map, WithoutVAOExtension) {
 
     DefaultFileSource fileSource(":memory:", "test/fixtures/api/assets");
 
-    Map map(test.backend, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/water.json"));
 
     test::checkImage("test/fixtures/map/no_vao", test::render(map, test.view), 0.002);
@@ -442,7 +447,7 @@ TEST(Map, WithoutVAOExtension) {
 TEST(Map, RemoveLayer) {
     MapTest test;
 
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadJSON(util::read_file("test/fixtures/api/empty.json"));
 
     auto layer = std::make_unique<BackgroundLayer>("background");
@@ -467,7 +472,7 @@ TEST(Map, DisabledSources) {
         return {};
     };
 
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
     map.setZoom(1);
 
     // This stylesheet has two raster layers, one that starts at zoom 1, the other at zoom 0.
@@ -517,7 +522,7 @@ TEST(Map, DisabledSources) {
 TEST(Map, DontLoadUnneededTiles) {
     MapTest test;
 
-    Map map(test.backend, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, test.observer, test.view.getSize(), 1, test.fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadJSON(R"STYLE({
   "sources": {
     "a": { "type": "vector", "tiles": [ "a/{z}/{x}/{y}" ] }
@@ -562,29 +567,14 @@ TEST(Map, DontLoadUnneededTiles) {
     }
 }
 
-
-class MockBackend : public HeadlessBackend {
-public:
-    MockBackend(std::shared_ptr<HeadlessDisplay> display_)
-            : HeadlessBackend(display_) {
-    }
-
-    std::function<void()> callback;
-    void invalidate() override {
-        if (callback) {
-            callback();
-        }
-    }
-};
-
 TEST(Map, TEST_DISABLED_ON_CI(ContinuousRendering)) {
     util::RunLoop runLoop;
-    MockBackend backend { test::sharedDisplay() };
+    MockBackend backend;
     BackendScope scope { backend };
     OffscreenView view { backend.getContext() };
     ThreadPool threadPool { 4 };
     DefaultFileSource fileSource(":memory:", "test/fixtures/api/assets");
-    Map map(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Continuous);
+    Map map(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Continuous);
 
     using namespace std::chrono_literals;
 
diff --git a/test/map/prefetch.test.cpp b/test/map/prefetch.test.cpp
index af2cd4e92f..47b39f7b88 100644
--- a/test/map/prefetch.test.cpp
+++ b/test/map/prefetch.test.cpp
@@ -27,7 +27,7 @@ TEST(Map, PrefetchTiles) {
     OffscreenView view(backend.getContext(), { 512, 512 });
     ThreadPool threadPool(4);
     StubFileSource fileSource;
-    Map map(backend, view.getSize(), 1, fileSource, threadPool, MapMode::Still);
+    Map map(backend, MapObserver::nullObserver(), view.getSize(), 1, fileSource, threadPool, MapMode::Still);
 
     std::vector<int> tiles;
 
diff --git a/test/util/memory.test.cpp b/test/util/memory.test.cpp
index bca538c6c6..8fd27f2462 100644
--- a/test/util/memory.test.cpp
+++ b/test/util/memory.test.cpp
@@ -74,7 +74,7 @@ private:
 TEST(Memory, Vector) {
     MemoryTest test;
 
-    Map map(test.backend, { 256, 256 }, 2, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, MapObserver::nullObserver(), { 256, 256 }, 2, test.fileSource, test.threadPool, MapMode::Still);
     map.setZoom(16); // more map features
     map.getStyle().loadURL("mapbox://streets");
 
@@ -84,7 +84,7 @@ TEST(Memory, Vector) {
 TEST(Memory, Raster) {
     MemoryTest test;
 
-    Map map(test.backend, { 256, 256 }, 2, test.fileSource, test.threadPool, MapMode::Still);
+    Map map(test.backend, MapObserver::nullObserver(), { 256, 256 }, 2, test.fileSource, test.threadPool, MapMode::Still);
     map.getStyle().loadURL("mapbox://satellite");
 
     test::render(map, test.view);
@@ -125,7 +125,7 @@ TEST(Memory, Footprint) {
 
     // Warm up buffers and cache.
     for (unsigned i = 0; i < 10; ++i) {
-        Map map(test.backend, { 256, 256 }, 2, test.fileSource, test.threadPool, MapMode::Still);
+        Map map(test.backend, MapObserver::nullObserver(), { 256, 256 }, 2, test.fileSource, test.threadPool, MapMode::Still);
         renderMap(map, "mapbox://streets");
         renderMap(map, "mapbox://satellite");
     };
@@ -139,8 +139,9 @@ TEST(Memory, Footprint) {
 
     long vectorInitialRSS = mbgl::test::getCurrentRSS();
     for (unsigned i = 0; i < runs; ++i) {
-        auto vector = std::make_unique<Map>(test.backend, Size{ 256, 256 }, 2, test.fileSource,
-                                            test.threadPool, MapMode::Still);
+        auto vector = std::make_unique<Map>(test.backend, MapObserver::nullObserver(),
+                                            Size{ 256, 256 }, 2, test.fileSource, test.threadPool,
+                                            MapMode::Still);
         renderMap(*vector, "mapbox://streets");
         maps.push_back(std::move(vector));
     };
@@ -149,8 +150,9 @@ TEST(Memory, Footprint) {
 
     long rasterInitialRSS = mbgl::test::getCurrentRSS();
     for (unsigned i = 0; i < runs; ++i) {
-        auto raster = std::make_unique<Map>(test.backend, Size{ 256, 256 }, 2, test.fileSource,
-                                            test.threadPool, MapMode::Still);
+        auto raster = std::make_unique<Map>(test.backend, MapObserver::nullObserver(),
+                                            Size{ 256, 256 }, 2, test.fileSource, test.threadPool,
+                                            MapMode::Still);
         renderMap(*raster, "mapbox://satellite");
         maps.push_back(std::move(raster));
     };