NOT FOR LANDING Implement WebMediaSession

content/renderer/media/android/webmediaplayer_android.h

Index: content/renderer/media/android/webmediaplayer_android.h
diff --git a/content/renderer/media/android/webmediaplayer_android.h b/content/renderer/media/android/webmediaplayer_android.h
index 5e96e8384204889a052bbd593e9bc4f5c9d2aaf1..22ad95bbe4f1c7055694666c4347bb76db0f7bf6 100644
--- a/content/renderer/media/android/webmediaplayer_android.h
+++ b/content/renderer/media/android/webmediaplayer_android.h
@@ -49,6 +49,7 @@ class WebContentDecryptionModuleResult;
 class WebFrame;
 class WebMediaPlayerClient;
 class WebMediaPlayerEncryptedMediaClient;
+class WebMediaSession;
 class WebURL;
 }
 
@@ -423,6 +424,9 @@ class WebMediaPlayerAndroid : public blink::WebMediaPlayer,
   // Player ID assigned by the |player_manager_|.
   int player_id_;
 
+  // Media Session ID.
+  int session_id_;
+
   // Current player states.
   blink::WebMediaPlayer::NetworkState network_state_;
   blink::WebMediaPlayer::ReadyState ready_state_;