1 files changed, 27 insertions, 23 deletions

diff --git a/chromium/third_party/blink/renderer/core/animation/document_timeline.cc b/chromium/third_party/blink/renderer/core/animation/document_timeline.cc
index 5fa2510929b..f907702ba1d 100644
--- a/chromium/third_party/blink/renderer/core/animation/document_timeline.cc
+++ b/chromium/third_party/blink/renderer/core/animation/document_timeline.cc
@@ -43,6 +43,7 @@
 #include "third_party/blink/renderer/core/page/page.h"
 #include "third_party/blink/renderer/platform/animation/compositor_animation_timeline.h"
 #include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
+#include "third_party/blink/renderer/platform/wtf/time.h"
 
 namespace blink {
 
@@ -59,24 +60,25 @@ bool CompareAnimations(const Member<Animation>& left,
 const double DocumentTimeline::kMinimumDelay = 0.04;
 
 DocumentTimeline* DocumentTimeline::Create(Document* document,
-                                           double origin_time_in_milliseconds,
+                                           TimeDelta origin_time,
                                            PlatformTiming* timing) {
-  return new DocumentTimeline(document, origin_time_in_milliseconds, timing);
+  return new DocumentTimeline(document, origin_time, timing);
 }
 
 DocumentTimeline* DocumentTimeline::Create(
     ExecutionContext* execution_context,
     const DocumentTimelineOptions& options) {
   Document* document = ToDocument(execution_context);
-  return new DocumentTimeline(document, options.originTime(), nullptr);
+  return new DocumentTimeline(
+      document, TimeDelta::FromMillisecondsD(options.originTime()), nullptr);
 }
 
 DocumentTimeline::DocumentTimeline(Document* document,
-                                   double origin_time_in_milliseconds,
+                                   TimeDelta origin_time,
                                    PlatformTiming* timing)
     : document_(document),
-      origin_time_(origin_time_in_milliseconds / 1000),
-      zero_time_(origin_time_),
+      origin_time_(origin_time),
+      zero_time_(TimeTicks() + origin_time_),
       zero_time_initialized_(false),
       outdated_animation_count_(0),
       playback_rate_(1),
@@ -188,9 +190,10 @@ void DocumentTimeline::ScheduleNextService() {
 }
 
 void DocumentTimeline::DocumentTimelineTiming::WakeAfter(double duration) {
-  if (timer_.IsActive() && timer_.NextFireInterval() < duration)
+  TimeDelta duration_delta = TimeDelta::FromSecondsD(duration);
+  if (timer_.IsActive() && timer_.NextFireInterval() < duration_delta)
     return;
-  timer_.StartOneShot(duration, FROM_HERE);
+  timer_.StartOneShot(duration_delta, FROM_HERE);
 }
 
 void DocumentTimeline::DocumentTimelineTiming::ServiceOnNextFrame() {
@@ -203,19 +206,17 @@ void DocumentTimeline::DocumentTimelineTiming::Trace(blink::Visitor* visitor) {
   DocumentTimeline::PlatformTiming::Trace(visitor);
 }
 
-double DocumentTimeline::ZeroTime() {
+TimeTicks DocumentTimeline::ZeroTime() {
   if (!zero_time_initialized_ && document_ && document_->Loader()) {
-    zero_time_ =
-        TimeTicksInSeconds(
-            document_->Loader()->GetTiming().ReferenceMonotonicTime()) +
-        origin_time_;
+    zero_time_ = document_->Loader()->GetTiming().ReferenceMonotonicTime() +
+                 origin_time_;
     zero_time_initialized_ = true;
   }
   return zero_time_;
 }
 
 void DocumentTimeline::ResetForTesting() {
-  zero_time_ = origin_time_;
+  zero_time_ = TimeTicks() + origin_time_;
   zero_time_initialized_ = true;
   playback_rate_ = 1;
   last_current_time_internal_ = 0;
@@ -225,17 +226,20 @@ double DocumentTimeline::currentTime(bool& is_null) {
   return CurrentTimeInternal(is_null) * 1000;
 }
 
+// TODO(npm): change the return type to base::Optional<TimeTicks>.
 double DocumentTimeline::CurrentTimeInternal(bool& is_null) {
   if (!IsActive()) {
     is_null = true;
     return std::numeric_limits<double>::quiet_NaN();
   }
-  double result =
-      playback_rate_ == 0
-          ? ZeroTime()
-          : (GetDocument()->GetAnimationClock().CurrentTime() - ZeroTime()) *
-                playback_rate_;
+  double result = playback_rate_ == 0
+                      ? TimeTicksInSeconds(ZeroTime())
+                      : (GetDocument()->GetAnimationClock().CurrentTime() -
+                         TimeTicksInSeconds(ZeroTime())) *
+                            playback_rate_;
   is_null = std::isnan(result);
+  // This looks like it could never be NaN here.
+  DCHECK(!is_null);
   return result;
 }
 
@@ -294,10 +298,10 @@ void DocumentTimeline::SetPlaybackRate(double playback_rate) {
     return;
   double current_time = CurrentTimeInternal();
   playback_rate_ = playback_rate;
-  zero_time_ = playback_rate == 0
-                   ? current_time
-                   : GetDocument()->GetAnimationClock().CurrentTime() -
-                         current_time / playback_rate;
+  zero_time_ = TimeTicksFromSeconds(
+      playback_rate == 0 ? current_time
+                         : GetDocument()->GetAnimationClock().CurrentTime() -
+                               current_time / playback_rate);
   zero_time_initialized_ = true;
 
   // Corresponding compositor animation may need to be restarted to pick up