Move audio focus control from media/ to content/ and make it per WebContents.

media/base/android/media_player_manager.h

Index: media/base/android/media_player_manager.h
diff --git a/media/base/android/media_player_manager.h b/media/base/android/media_player_manager.h
index feac84e9193120c215b4afe7f0113008cd9f6981..d2d35f471f03e450b52d4ce2f17f9c301d5f5783 100644
--- a/media/base/android/media_player_manager.h
+++ b/media/base/android/media_player_manager.h
@@ -78,6 +78,12 @@ class MEDIA_EXPORT MediaPlayerManager {
 
   // Called by the player to get a hardware protected surface.
   virtual void RequestFullScreen(int player_id) = 0;
+
+  // Called by the player to request to play. The manager should use this
+  // opportunity to check if the current context is appropriate for a media to
+  // play.
+  // Returns whether the request was granted.
+  virtual bool RequestPlay(int player_id) = 0;

[whywhat, 2015/05/12 12:50:47]

nit: s/RequestPlay/{CanPlay|IsAllowedToPlay}?

[mlamouri (slow - plz ping), 2015/05/19 21:56:17]

I used ::RequestPlay() because it's not just returning a boolean, it's doing
things. CanPlay() or IsAllowedToPlay() might give the wrong impression that this
is just going to return true/false with no side effects.

 };
 
 }  // namespace media