[Video] Record the results of background video optimization checks.

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 96ba8b569f4cc125fcd33c88f230e590f4ec849a..0bb3a568e59bef67d1eca4aa101e2c64bcbc2017 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -2195,12 +2195,23 @@ bool WebMediaPlayerImpl::ShouldPauseVideoWhenHidden() const {
       return false;
 
 #if defined(OS_ANDROID)
-    if (IsRemote())
+    if (IsRemote()) {
+      UMA_HISTOGRAM_ENUMERATION("Media.Video.ShouldPauseVideoWhenHiddenResult",
+                                BackgroundOptimizationResult::FAIL_FOR_REMOTE,
+                                BackgroundOptimizationResult::RESULT_MAX + 1);
       return false;
+    }
 #endif
 
-    return !HasAudio() || (IsResumeBackgroundVideosEnabled() &&
-                           video_locked_when_paused_when_hidden_);
+    if (!HasAudio()) {
+      ReportBackgroundOptimizationResult(
+          BackgroundOptimizationResult::SUCCESS_FOR_VIDEO_ONLY);
+      return true;
+    }
+
+    // Non an optimization so don't record the result.
+    return IsResumeBackgroundVideosEnabled() &&
+           video_locked_when_paused_when_hidden_;
   }
 
   // Otherwise only pause if the optimization is on and it's a video-only
@@ -2222,20 +2233,33 @@ bool WebMediaPlayerImpl::ShouldDisableVideoWhenHidden() const {
 bool WebMediaPlayerImpl::IsBackgroundOptimizationCandidate() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
+  // Never optimize audio-only players.
+  if (!HasVideo())
+    return false;
+
 #if defined(OS_ANDROID)  // WMPI_CAST
   // Don't optimize players being Cast.
-  if (IsRemote())
+  if (IsRemote()) {
+    ReportBackgroundOptimizationResult(
+        BackgroundOptimizationResult::FAIL_FOR_REMOTE);
     return false;
+  }
 
   // Video-only players are always optimized (paused) on Android.
   // Don't check the keyframe distance and duration.
-  if (!HasAudio() && HasVideo())
+  if (!HasAudio()) {
+    ReportBackgroundOptimizationResult(
+        BackgroundOptimizationResult::SUCCESS_FOR_VIDEO_ONLY);
     return true;
+  }
 #endif  // defined(OS_ANDROID)
 
   // Don't optimize audio-only or streaming players.
-  if (!HasVideo() || IsStreaming())
+  if (IsStreaming()) {
+    ReportBackgroundOptimizationResult(
+        BackgroundOptimizationResult::FAIL_FOR_STREAMING);
     return false;
+  }
 
   // Videos shorter than the maximum allowed keyframe distance can be optimized.
   base::TimeDelta duration = GetPipelineMediaDuration();
@@ -2243,12 +2267,33 @@ bool WebMediaPlayerImpl::IsBackgroundOptimizationCandidate() const {
       (load_type_ == kLoadTypeMediaSource)
           ? max_keyframe_distance_to_disable_background_video_mse_
           : max_keyframe_distance_to_disable_background_video_;
-  if (duration < max_keyframe_distance)
+  if (duration < max_keyframe_distance) {
+    ReportBackgroundOptimizationResult(
+        BackgroundOptimizationResult::SUCCESS_FOR_DURATION);
     return true;
+  }
 
   // Otherwise, only optimize videos with shorter average keyframe distance.
   PipelineStatistics stats = GetPipelineStatistics();
-  return stats.video_keyframe_distance_average < max_keyframe_distance;
+  bool is_candidate =
+      stats.video_keyframe_distance_average < max_keyframe_distance;
+  ReportBackgroundOptimizationResult(
+      is_candidate ? BackgroundOptimizationResult::SUCCESS_FOR_KEYFRAME_DISTANCE
+                   : BackgroundOptimizationResult::FAIL_FOR_KEYFRAME_DISTANCE);
+  return is_candidate;
+}
+
+void WebMediaPlayerImpl::ReportBackgroundOptimizationResult(
+    BackgroundOptimizationResult result) const {
+  if (HasAudio()) {
+    UMA_HISTOGRAM_ENUMERATION("Media.Video.ShouldDisableVideoWhenHiddenResult",
+                              result,
+                              BackgroundOptimizationResult::RESULT_MAX + 1);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION("Media.Video.ShouldPauseVideoWhenHiddenResult",
+                              result,
+                              BackgroundOptimizationResult::RESULT_MAX + 1);
+  }
 }
 
 void WebMediaPlayerImpl::UpdateBackgroundVideoOptimizationState() {