Merge M59: "Start reporting watch time if ABR adapts above 200p."

Previously we only checked the initial resolution and assumed it
was always large enough to start watch time reporting; clearly
this is not true since YouTube offers a 140p format.

Probably we also want to drop the minimum resolution to 200x140p,
which I'll check with product about and handle in a followup CL.

BUG=711792
TEST=new tests. Manual: force 140p, adapt above, verify watch time.

Review-Url: https://codereview.chromium.org/2822543006
Cr-Commit-Position: refs/heads/master@{#464826}
(cherry picked from commit 2540556)

Review-Url: https://codereview.chromium.org/2819323002 .
Cr-Commit-Position: refs/branch-heads/3071@{#21}
Cr-Branched-From: a106f0a-refs/heads/master@{#464641}

media/blink/watch_time_reporter.cc

@@ -162,6 +162,11 @@ void WatchTimeReporter::OnHidden() {
   MaybeFinalizeWatchTime(FinalizeTime::ON_NEXT_UPDATE);
 }
 
+bool WatchTimeReporter::IsSizeLargeEnoughToReportWatchTime() const {
+  return initial_video_size_.height() >= kMinimumVideoSize.height() &&
+         initial_video_size_.width() >= kMinimumVideoSize.width();
+}
+
 void WatchTimeReporter::OnPowerStateChange(bool on_battery_power) {
   if (!reporting_timer_.IsRunning())
     return;
@@ -184,9 +189,7 @@ bool WatchTimeReporter::ShouldReportWatchTime() {
   // Report listen time or watch time only for tracks that are audio-only or
   // have both an audio and video track of sufficient size.
   return (!has_video_ && has_audio_) ||
-         (has_video_ && has_audio_ &&
-          initial_video_size_.height() >= kMinimumVideoSize.height() &&
-          initial_video_size_.width() >= kMinimumVideoSize.width());
+         (has_video_ && has_audio_ && IsSizeLargeEnoughToReportWatchTime());
 }
 
 void WatchTimeReporter::MaybeStartReportingTimer(

media/blink/watch_time_reporter.h

@@ -103,6 +103,10 @@ class MEDIA_BLINK_EXPORT WatchTimeReporter : base::PowerObserver {
   void OnShown();
   void OnHidden();
 
+  // Returns true if the current size is large enough that watch time will be
+  // recorded for playback.
+  bool IsSizeLargeEnoughToReportWatchTime() const;
+
   // Setup the reporting interval to be immediate to avoid spinning real time
   // within the unit test.
   void set_reporting_interval_for_testing() {

media/blink/watch_time_reporter_unittest.cc

@@ -279,39 +279,48 @@ TEST_P(WatchTimeReporterTest, WatchTimeReporter) {
   Initialize(!has_video_, true, true, gfx::Size());
   wtr_->OnPlaying();
   EXPECT_EQ(!has_video_, IsMonitoring());
+  EXPECT_FALSE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, true, true, gfx::Size());
   wtr_->OnPlaying();
   EXPECT_EQ(!has_video_, IsMonitoring());
+  EXPECT_FALSE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   constexpr gfx::Size kSizeTooSmall = gfx::Size(100, 100);
   Initialize(!has_video_, true, true, kSizeTooSmall);
   wtr_->OnPlaying();
   EXPECT_EQ(!has_video_, IsMonitoring());
+  EXPECT_FALSE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, true, true, kSizeJustRight);
   wtr_->OnPlaying();
   EXPECT_TRUE(IsMonitoring());
+  EXPECT_TRUE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, false, false, kSizeJustRight);
   wtr_->OnPlaying();
   EXPECT_TRUE(IsMonitoring());
+  EXPECT_TRUE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, true, false, kSizeJustRight);
   wtr_->OnPlaying();
   EXPECT_TRUE(IsMonitoring());
+  EXPECT_TRUE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, true, true, gfx::Size());
   wtr_->OnPlaying();
   EXPECT_EQ(!has_video_, IsMonitoring());
+  EXPECT_FALSE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, false, false, gfx::Size());
   wtr_->OnPlaying();
   EXPECT_EQ(!has_video_, IsMonitoring());
+  EXPECT_FALSE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   Initialize(true, true, false, gfx::Size());
   wtr_->OnPlaying();
   EXPECT_EQ(!has_video_, IsMonitoring());
+  EXPECT_FALSE(wtr_->IsSizeLargeEnoughToReportWatchTime());
 
   if (!has_video_)
     EXPECT_WATCH_TIME_FINALIZED();

media/blink/webmediaplayer_impl.cc

@@ -1419,13 +1419,13 @@ void WebMediaPlayerImpl::OnVideoNaturalSizeChange(const gfx::Size& size) {
   if (overlay_enabled_ && surface_manager_)
     surface_manager_->NaturalSizeChanged(rotated_size);
 
-  gfx::Size old_size = pipeline_metadata_.natural_size;
   pipeline_metadata_.natural_size = rotated_size;
-  if (old_size.IsEmpty()) {
-    // WatchTimeReporter doesn't report metrics for empty videos. Re-create
-    // |watch_time_reporter_| if we didn't originally know the video size.
+
+  // Re-create |watch_time_reporter_| if we didn't originally know the video
+  // size or the previous size was too small for reporting.
+  if (!watch_time_reporter_->IsSizeLargeEnoughToReportWatchTime())
     CreateWatchTimeReporter();
-  }
+
   client_->SizeChanged();
 
   if (observer_)