Pause EME player whose external surface is stolen by another player

content/public/browser/android/external_video_surface_container.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_ANDROID_EXTERNAL_VIDEO_SURFACE_CONTAINER_H_
 #define CONTENT_PUBLIC_BROWSER_ANDROID_EXTERNAL_VIDEO_SURFACE_CONTAINER_H_
 
 #include <jni.h>
 
 #include "base/callback.h"
 #include "content/common/content_export.h"
 
 namespace gfx {
 class RectF;
 }
 
 namespace content {
 class WebContents;
 
 // An interface used for managing the video surface for the hole punching.
 class CONTENT_EXPORT ExternalVideoSurfaceContainer {
  public:
   typedef base::Callback<void(int, jobject)> SurfaceCreatedCB;
   typedef base::Callback<void(int)> SurfaceDestroyedCB;
+  static const int kInvalidPlayerId = -1;
 
   // Called when a media player wants to request an external video surface.
   // Whenever the surface is created and visible, |surface_created_cb| will be
   // called.  And whenever it is destroyed or invisible, |surface_destroyed_cb|
   // will be called.
   virtual void RequestExternalVideoSurface(
       int player_id,
       const SurfaceCreatedCB& surface_created_cb,
       const SurfaceDestroyedCB& surface_destroyed_cb) = 0;
 
-  // Called when a media player wants to release an external video surface.
+  // Returns id of player currently using the external video surface.
+  // Returns kInvalidPlayerId if no player uses the surface.
+  virtual int GetCurrentPlayerId() = 0;
+
+  // Called when a media player wants to release a certain player's external
+  // video surface.
   virtual void ReleaseExternalVideoSurface(int player_id) = 0;
 
   // Called when the position and size of the video element which uses
   // the external video surface is changed.
   // |rect| contains the new position and size in css pixels.
   virtual void OnExternalVideoSurfacePositionChanged(
       int player_id, const gfx::RectF& rect) = 0;
 
   // Called when the page that contains the video element is scrolled or zoomed.
   virtual void OnFrameInfoUpdated() = 0;
 
   virtual ~ExternalVideoSurfaceContainer() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_ANDROID_EXTERNAL_VIDEO_SURFACE_CONTAINER_H_