EME: Handle NO_KEY and resume playback after key is added.

media/base/android/media_player_android.h

Index: media/base/android/media_player_android.h
diff --git a/media/base/android/media_player_android.h b/media/base/android/media_player_android.h
index 06cb573a436226531c548511a24a4c4f0c30d7a2..a767e5f172446f03e4ffc22bef961182d7a1f36a 100644
--- a/media/base/android/media_player_android.h
+++ b/media/base/android/media_player_android.h
@@ -102,6 +102,10 @@ class MEDIA_EXPORT MediaPlayerAndroid {
   // Pass a drm bridge to a player.
   virtual void SetDrmBridge(MediaDrmBridge* drm_bridge);
 
+  // Notifies the player that a decryption key has been added. The player
+  // may want to start/resume playback if it is waiting for a key.
+  virtual void OnKeyAdded();
+
   int player_id() { return player_id_; }
 
  protected: