Implement media Cast button in Blink

content/common/media/media_player_messages_android.h

Index: content/common/media/media_player_messages_android.h
diff --git a/content/common/media/media_player_messages_android.h b/content/common/media/media_player_messages_android.h
index 4548f0b849b05010f755cea891495490f86a2b8a..8bb75045602d5be6bba6b4478dcd9fa39ad8cbb3 100644
--- a/content/common/media/media_player_messages_android.h
+++ b/content/common/media/media_player_messages_android.h
@@ -196,6 +196,11 @@ IPC_MESSAGE_ROUTED2(MediaPlayerMsg_ConnectedToRemoteDevice,
 IPC_MESSAGE_ROUTED1(MediaPlayerMsg_DisconnectedFromRemoteDevice,
                     int /* player_id */)
 
+// The availability of remote devices has changed
+IPC_MESSAGE_ROUTED2(MediaPlayerMsg_RemoteRouteAvailabilityChanged,
+                    int /* player_id */,
+                    bool /* routes_available */)
+
 // Instructs the video element to enter fullscreen.
 IPC_MESSAGE_ROUTED1(MediaPlayerMsg_RequestFullscreen,
                     int /*player_id */)
@@ -246,6 +251,14 @@ IPC_MESSAGE_ROUTED1(MediaPlayerHostMsg_EnterFullscreen, int /* player_id */)
 // Requests the player to exit fullscreen.
 IPC_MESSAGE_ROUTED1(MediaPlayerHostMsg_ExitFullscreen, int /* player_id */)
 
+// Play the media on a remote device, if possible.
+IPC_MESSAGE_ROUTED1(MediaPlayerHostMsg_RequestRemotePlayback,
+                    int /* demuxer_client_id */)
+
+// Control media playing on a remote device.
+IPC_MESSAGE_ROUTED1(MediaPlayerHostMsg_RequestRemotePlaybackControl,
+                    int /* demuxer_client_id */)
+
 // Requests the player with |player_id| to use the CDM with |cdm_id|.
 IPC_MESSAGE_ROUTED2(MediaPlayerHostMsg_SetCdm,
                     int /* player_id */,