ui: Cleanup class/struct forward declarations

content/renderer/media/android/webmediaplayer_android.cc

Index: content/renderer/media/android/webmediaplayer_android.cc
diff --git a/content/renderer/media/android/webmediaplayer_android.cc b/content/renderer/media/android/webmediaplayer_android.cc
index bf104c6056109e9c8ee7d448f58250c3177e911d..0a160a3a102d922329c0241a152941bd2e7d56c5 100644
--- a/content/renderer/media/android/webmediaplayer_android.cc
+++ b/content/renderer/media/android/webmediaplayer_android.cc
@@ -880,6 +880,11 @@ void WebMediaPlayerAndroid::OnCancelledRemotePlaybackRequest() {
   client_->cancelledRemotePlaybackRequest();
 }
 
+void WebMediaPlayerAndroid::OnRemotePlaybackStarted() {
+  DCHECK(main_thread_checker_.CalledOnValidThread());
+  client_->remotePlaybackStarted();
+}
+
 void WebMediaPlayerAndroid::OnDidExitFullscreen() {
   SetNeedsEstablishPeer(true);
   // We had the fullscreen surface connected to Android MediaPlayer,