Add UMA for droppedframes count

media/base/pipeline.cc

Index: media/base/pipeline.cc
diff --git a/media/base/pipeline.cc b/media/base/pipeline.cc
index bc55981f6cfbdbaf96e29f2d1c50da616d6b624a..c2e68112dd61767460dd30ed5cfdccd267225eb9 100644
--- a/media/base/pipeline.cc
+++ b/media/base/pipeline.cc
@@ -624,6 +624,9 @@ void Pipeline::StopTask(const base::Closure& stop_cb) {
   if (state_ == kStopping)
     return;
 
+  PipelineStatistics stats = GetStatistics();
+  UMA_HISTOGRAM_COUNTS("Media.DroppedFrameCount", stats.video_frames_dropped);

[scherkus (not reviewing), 2014/08/26 21:41:04]

here's where things get subtle/tricky ... do we want to record this stat even
for Pipelines that don't contain video? (e.g., mp3s)

do we want to record this stat for Pipelines that never even successfully start
playing?

+
   SetState(kStopping);
   pending_callbacks_.reset();
   DoStop(base::Bind(&Pipeline::OnStopCompleted, weak_factory_.GetWeakPtr()));