[Video] Don't pause video-only elements if they're already paused...

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 d908e699612de5a34dddc5fa6138d31b45e683d3..3194070ab8ba022c3bb0e77a29c646b02fd87f63 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -1161,7 +1161,10 @@ void WebMediaPlayerImpl::OnPipelineResumed() {
   is_pipeline_resuming_ = false;
 
   if (IsHidden()) {
-    DisableVideoTrackIfNeeded();
+    if (ShouldPauseVideoWhenHidden())
+      PauseVideoIfNeeded();
+    else
+      DisableVideoTrackIfNeeded();
   } else {
     EnableVideoTrackIfNeeded();
   }
@@ -1411,13 +1414,8 @@ void WebMediaPlayerImpl::OnFrameHidden() {
     watch_time_reporter_->OnHidden();
 
   if (ShouldPauseVideoWhenHidden()) {
-    if (!paused_when_hidden_) {
-      // OnPause() will set |paused_when_hidden_| to false and call
-      // UpdatePlayState(), so set the flag to true after and then return.
-      OnPause();
-      paused_when_hidden_ = true;
-      return;
-    }
+    PauseVideoIfNeeded();
+    return;
   } else {
     DisableVideoTrackIfNeeded();
   }
@@ -2182,6 +2180,16 @@ bool WebMediaPlayerImpl::IsBackgroundOptimizationCandidate() const {
          max_keyframe_distance_to_disable_background_video_;
 }
 
+void WebMediaPlayerImpl::PauseVideoIfNeeded() {
+  if (is_pipeline_resuming_ || seeking_ || paused_ || paused_when_hidden_)

[sandersd (OOO until July 31), 2017/01/20 21:24:19]

Require or DCHECK IsHidden?

Do we need to also check if the pipeline has been started yet?

+    return;
+
+  // OnPause() will set |paused_when_hidden_| to false and call
+  // UpdatePlayState(), so set the flag to true after and then return.
+  OnPause();
+  paused_when_hidden_ = true;
+}
+
 void WebMediaPlayerImpl::EnableVideoTrackIfNeeded() {
   DCHECK(!IsHidden());