[Media] Disable background video optimization for streaming videos

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 b6a56c2cd26dce38c4fc4676e610e77460f315e6..8eb02693afd99a472a4c8fbe47977d8687dca320 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -1336,7 +1336,7 @@ void WebMediaPlayerImpl::OnVideoOpacityChange(bool opaque) {
 void WebMediaPlayerImpl::OnHidden() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
-  if (IsBackgroundVideoTrackOptimizationEnabled())
+  if (!IsStreaming() && IsBackgroundVideoTrackOptimizationEnabled())
     selectedVideoTrackChanged(nullptr);
 
   if (watch_time_reporter_)
@@ -1354,7 +1354,7 @@ void WebMediaPlayerImpl::OnShown() {
   if (watch_time_reporter_)
     watch_time_reporter_->OnShown();
 
-  if (IsBackgroundVideoTrackOptimizationEnabled() &&
+  if (!IsStreaming() && IsBackgroundVideoTrackOptimizationEnabled() &&
       client_->hasSelectedVideoTrack()) {
     WebMediaPlayer::TrackId trackId = client_->getSelectedVideoTrackId();
     selectedVideoTrackChanged(&trackId);
@@ -1648,7 +1648,7 @@ void WebMediaPlayerImpl::StartPipeline() {
   // TODO(sandersd): FileSystem objects may also be non-static, but due to our
   // caching layer such situations are broken already. http://crbug.com/593159
   bool is_static = !chunk_demuxer_;
-  bool is_streaming = data_source_ && data_source_->IsStreaming();
+  bool is_streaming = IsStreaming();
   UMA_HISTOGRAM_BOOLEAN("Media.IsStreaming", is_streaming);
 
   // ... and we're ready to go!
@@ -1737,7 +1737,7 @@ void WebMediaPlayerImpl::UpdatePlayState() {
   bool is_streaming = false;
 #else
   bool is_remote = false;
-  bool is_streaming = data_source_ && data_source_->IsStreaming();
+  bool is_streaming = IsStreaming();
 #endif
 
   bool is_suspended = pipeline_controller_.IsSuspended();
@@ -2030,6 +2030,11 @@ bool WebMediaPlayerImpl::IsHidden() const {
   return delegate_ && delegate_->IsHidden();
 }
 
+bool WebMediaPlayerImpl::IsStreaming() const {
+  return !std::isfinite(duration()) ||

[sandersd (OOO until July 31), 2017/01/06 21:20:28]

FYI: I was just looking through this code, and everything else is using
video_stream->liveness(). This is the bit that enables low-delay decoding, so
it's worth verifying that the computation is the same.

[whywhat, 2017/01/06 22:19:57]

Hm, liveness seems to depend on the stream parser:
- ffmpeg checks for duration to be infinite:
https://cs.chromium.org/chromium/src/media/formats/webm/webm_stream_parser.cc...
- chunk (webm stream?) checks for negative duration:
https://cs.chromium.org/chromium/src/media/formats/webm/webm_stream_parser.cc...

I'm happy to use that but need to find a way to propagate it from demuxer stream
to WMPI

+         (data_source_ && data_source_->IsStreaming());
+}
+
 bool WebMediaPlayerImpl::DoesOverlaySupportMetadata() const {
   return pipeline_metadata_.video_rotation == VIDEO_ROTATION_0;
 }