Delete browser MSE implementation.

content/browser/media/android/media_player_renderer.cc

Index: content/browser/media/android/media_player_renderer.cc
diff --git a/content/browser/media/android/media_player_renderer.cc b/content/browser/media/android/media_player_renderer.cc
index 303f532605efa2ac8237ff930f46ed1b8d03078d..980d3dbcd1b8c2c380fb226df808fcddadf17c34 100644
--- a/content/browser/media/android/media_player_renderer.cc
+++ b/content/browser/media/android/media_player_renderer.cc
@@ -194,10 +194,6 @@ void MediaPlayerRenderer::OnVideoSizeChanged(int player_id,
   renderer_client_->OnVideoNaturalSizeChange(video_size_);
 }
 
-void MediaPlayerRenderer::OnWaitingForDecryptionKey(int player_id) {
-  NOTREACHED();
-}
-
 media::MediaPlayerAndroid* MediaPlayerRenderer::GetFullscreenPlayer() {
   NOTREACHED();
   return nullptr;