[Media, Video] Enable the video track for a new renderer.

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 c9b8f8a465bd5590c4dca4fb7af1538961b429bd..3055c3dcb62d107e2190474c0b1f20b8064813ef 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -200,6 +200,7 @@ WebMediaPlayerImpl::WebMediaPlayerImpl(
                      base::Unretained(this)),
           base::Bind(&WebMediaPlayerImpl::OnPipelineSeeked, AsWeakPtr()),
           base::Bind(&WebMediaPlayerImpl::OnPipelineSuspended, AsWeakPtr()),
+          base::Bind(&WebMediaPlayerImpl::OnPipelineResumed, AsWeakPtr()),
           base::Bind(&WebMediaPlayerImpl::OnError, AsWeakPtr())),
       load_type_(LoadTypeURL),
       opaque_(false),
@@ -470,6 +471,19 @@ void WebMediaPlayerImpl::pause() {
   DCHECK(watch_time_reporter_);
   watch_time_reporter_->OnPaused();
   media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::PAUSE));
+
+  // Enable the background video track back so that when the new renderer is
+  // initialized upon resume, it registers itself with the video track.
+  // TODO(avayvod): Remove when disabling video tracks works correctly. See
+  //                https://crbug.com/678374.
+  if (video_track_disabled_) {
+    video_track_disabled_ = false;
+    if (client_->hasSelectedVideoTrack()) {
+      WebMediaPlayer::TrackId trackId = client_->getSelectedVideoTrackId();
+      selectedVideoTrackChanged(&trackId);
+    }
+  }
+
   UpdatePlayState();
 }
 
@@ -667,9 +681,7 @@ void WebMediaPlayerImpl::selectedVideoTrackChanged(
 
   std::ostringstream logstr;
   std::vector<MediaTrack::Id> selectedVideoMediaTrackId;
-  bool canAddVideoTrack =
-      !IsBackgroundVideoTrackOptimizationEnabled() || !IsHidden();
-  if (selectedTrackId && canAddVideoTrack) {
+  if (selectedTrackId && !video_track_disabled_) {
     selectedVideoMediaTrackId.push_back(selectedTrackId->utf8().data());
     logstr << selectedVideoMediaTrackId[0];
   }
@@ -1054,8 +1066,11 @@ void WebMediaPlayerImpl::OnCdmAttached(bool success) {
 }
 
 void WebMediaPlayerImpl::OnPipelineSeeked(bool time_updated) {
-  seeking_ = false;
-  seek_time_ = base::TimeDelta();
+  if (seeking_) {

[sandersd (OOO until July 31), 2017/01/07 00:56:17]

Shouldn't be needed anymore?

[whywhat, 2017/01/07 02:02:35]

Done.

+    seeking_ = false;
+    seek_time_ = base::TimeDelta();
+  }
+
   if (paused_) {
 #if defined(OS_ANDROID)  // WMPI_CAST
     if (isRemote()) {
@@ -1103,6 +1118,18 @@ void WebMediaPlayerImpl::OnPipelineSuspended() {
   }
 }
 
+void WebMediaPlayerImpl::OnPipelineResumed() {
+  // Disable video track if we start playing the video in the background and
+  // haven't disabled the decoder yet.
+  // TODO(avayvod): Remove this when disabling and enabling video tracks in
+  // non-playing state works correctly. See https://crbug.com/678374.
+  if (IsBackgroundVideoTrackOptimizationEnabled() && IsHidden() &&
+      !video_track_disabled_) {
+    video_track_disabled_ = true;
+    selectedVideoTrackChanged(nullptr);
+  }
+}
+
 void WebMediaPlayerImpl::OnDemuxerOpened() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   client_->mediaSourceOpened(
@@ -1336,14 +1363,21 @@ void WebMediaPlayerImpl::OnVideoOpacityChange(bool opaque) {
 void WebMediaPlayerImpl::OnHidden() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
-  if (IsBackgroundVideoTrackOptimizationEnabled())
-    selectedVideoTrackChanged(nullptr);
-
   if (watch_time_reporter_)
     watch_time_reporter_->OnHidden();
 
   UpdatePlayState();
 
+  // Only disable video tracks for background videos when they're playing.
+  // Otherwise the video track will get detached from the renderer.
+  // TODO(avayvod): Remove extra check once this is no longer happening.
+  //                See https://crbug.com/678374.
+  if (IsBackgroundVideoTrackOptimizationEnabled() &&
+      delegate_state_ == DelegateState::PLAYING) {
+    video_track_disabled_ = true;
+    selectedVideoTrackChanged(nullptr);
+  }
+
   // Schedule suspended playing media to be paused if the user doesn't come back
   // to it within some timeout period to avoid any autoplay surprises.
   ScheduleIdlePauseTimer();
@@ -1359,15 +1393,17 @@ void WebMediaPlayerImpl::OnShown() {
       base::Bind(&VideoFrameCompositor::SetForegroundTime,
                  base::Unretained(compositor_), base::TimeTicks::Now()));
 
-  if (IsBackgroundVideoTrackOptimizationEnabled() &&
-      client_->hasSelectedVideoTrack()) {
-    WebMediaPlayer::TrackId trackId = client_->getSelectedVideoTrackId();
-    selectedVideoTrackChanged(&trackId);
-  }
-
   must_suspend_ = false;
   background_pause_timer_.Stop();
 
+  if (video_track_disabled_) {
+    video_track_disabled_ = false;
+    if (client_->hasSelectedVideoTrack()) {
+      WebMediaPlayer::TrackId trackId = client_->getSelectedVideoTrackId();
+      selectedVideoTrackChanged(&trackId);
+    }
+  }
+
   UpdatePlayState();
 }