ui: Cleanup class/struct forward declarations

chrome/browser/media/android/remote/remote_media_player_manager.cc

Index: chrome/browser/media/android/remote/remote_media_player_manager.cc
diff --git a/chrome/browser/media/android/remote/remote_media_player_manager.cc b/chrome/browser/media/android/remote/remote_media_player_manager.cc
index cb5eef54aebb2277a8131295e0bca0d61439bb16..e5dcc15dc913069ef969ff7b7b21f15daf6b754b 100644
--- a/chrome/browser/media/android/remote/remote_media_player_manager.cc
+++ b/chrome/browser/media/android/remote/remote_media_player_manager.cc
@@ -208,6 +208,10 @@ void RemoteMediaPlayerManager::OnRemoteDeviceUnselected(int player_id) {
   ReplaceRemotePlayerWithLocal(player_id);
 }
 
+void RemoteMediaPlayerManager::OnRemotePlaybackStarted(int player_id) {
+  Send(new MediaPlayerMsg_RemotePlaybackStarted(RoutingID(), player_id));
+}
+
 void RemoteMediaPlayerManager::OnRemotePlaybackFinished(int player_id) {
   ReplaceRemotePlayerWithLocal(player_id);
 }