Bug 1319706. Part 4 - add some logs to debug 'ended' not fired. r=kaku

MozReview-Commit-ID: ATqszBBdo1P

--HG--
extra : rebase_source : 12f417d5dd29849ab16305f9c902ee9e9fb4e19a
extra : intermediate-source : 277bfa2e67ef58b51848c0a1d6986e8eb3222492
extra : source : 01f99c635d516b05a8f0781a6d0ff11123708481

dom/media/MediaDecoder.cpp

@@ -985,9 +985,14 @@ MediaDecoder::PlaybackEnded()
   MOZ_DIAGNOSTIC_ASSERT(!IsShutdown());
 
   if (mLogicallySeeking || mPlayState == PLAY_STATE_LOADING) {
+    DECODER_LOG("MediaDecoder::PlaybackEnded bailed out, "
+                "mLogicallySeeking=%d mPlayState=%s",
+                mLogicallySeeking.Ref(), ToPlayStateStr(mPlayState));
     return;
   }
 
+  DECODER_LOG("MediaDecoder::PlaybackEnded");
+
   ChangeState(PLAY_STATE_ENDED);
   InvalidateWithFlags(VideoFrameContainer::INVALIDATE_FORCE);
   mOwner->PlaybackEnded();