Directly call ChunkDemuxer::Initialize completion callback.

media/filters/chunk_demuxer.cc

Index: media/filters/chunk_demuxer.cc
diff --git a/media/filters/chunk_demuxer.cc b/media/filters/chunk_demuxer.cc
index 443c7c5558873ff0326294e29c72a53bb6ca0ab3..d9a1f5c1d86169650e12b8b1ec7705a38e501bcf 100644
--- a/media/filters/chunk_demuxer.cc
+++ b/media/filters/chunk_demuxer.cc
@@ -432,15 +432,20 @@ void ChunkDemuxer::Initialize(
   DVLOG(1) << "Init()";
 
   base::AutoLock auto_lock(lock_);
-
-  // The |init_cb_| must only be run after this method returns, so always post.
-  init_cb_ = BindToCurrentLoop(cb);
   if (state_ == SHUTDOWN) {
-    base::ResetAndReturn(&init_cb_).Run(DEMUXER_ERROR_COULD_NOT_OPEN);
+    // Init cb must only be run after this method returns, so always post.
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(cb, DEMUXER_ERROR_COULD_NOT_OPEN));
     return;
   }
+
   DCHECK_EQ(state_, WAITING_FOR_INIT);
   host_ = host;
+  // Do not post init_cb once this function returns because if there is an
+  // error after initialization, the error might be reported before init_cb
+  // has a chance to run. This is because ChunkDemuxer::ReportError_Locked
+  // directly calls DemuxerHost::OnDemuxerError: crbug.com/633016.
+  init_cb_ = cb;
   enable_text_ = enable_text_tracks;
 
   ChangeState_Locked(INITIALIZING);