Bug 1258410: [MSE] P2. Disconnect init promise if any pending. r=gerald

MozReview-Commit-ID: 9iOPqSeDzdH

--HG--
extra : rebase_source : a5a840c31c7f5348870dc9f9ca3a408d91a96a88

dom/media/mediasource/TrackBuffersManager.cpp

@@ -308,6 +308,13 @@ TrackBuffersManager::CompleteResetParserState()
   MOZ_ASSERT(OnTaskQueue());
   MSE_DEBUG("");
 
+  // We shouldn't change mInputDemuxer while a demuxer init/reset request is
+  // being processed. See bug 1239983.
+  NS_ASSERTION(!mDemuxerInitRequest.Exists(), "Previous AppendBuffer didn't complete");
+  if (mDemuxerInitRequest.Exists()) {
+    mDemuxerInitRequest.Disconnect();
+  }
+
   for (auto& track : GetTracksList()) {
     // 2. Unset the last decode timestamp on all track buffers.
     // 3. Unset the last frame duration on all track buffers.
@@ -882,7 +889,7 @@ TrackBuffersManager::OnDemuxerInitDone(nsresult)
   if (!mInputDemuxer) {
     // mInputDemuxer shouldn't have been destroyed while a demuxer init/reset
     // request was being processed. See bug 1239983.
-    NS_WARNING("mInputDemuxer has been destroyed");
+    NS_ASSERTION(false, "mInputDemuxer has been destroyed");
     RejectAppend(NS_ERROR_ABORT, __func__);
   }