Avoid double task trampoline for Pipeline state transitions.

media/filters/ffmpeg_demuxer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/ffmpeg_demuxer.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/base64.h"
@@ skipping 675 matching lines @@
   // don't use.  FFmpeg will only read ID3v1 tags if no other metadata is
   // available, so add a metadata entry to ensure some is always present.
   av_dict_set(&format_context->metadata, "skip_id3v1_tags", "", 0);
 
   // Ensure ffmpeg doesn't give up too early while looking for stream params;
   // this does not increase the amount of data downloaded.  The default value
   // is 5 AV_TIME_BASE units (1 second each), which prevents some oddly muxed
   // streams from being detected properly; this value was chosen arbitrarily.
   format_context->max_analyze_duration2 = 60 * AV_TIME_BASE;
 
+  // Always post the callback because |this| could be destroyed upon failure.
+  PipelineStatusCB bound_status_cb = BindToCurrentLoop(status_cb);
+
   // Open the AVFormatContext using our glue layer.
   CHECK(blocking_thread_.Start());
   base::PostTaskAndReplyWithResult(
       blocking_thread_.message_loop_proxy().get(),
       FROM_HERE,
       base::Bind(&FFmpegGlue::OpenContext, base::Unretained(glue_.get())),
       base::Bind(&FFmpegDemuxer::OnOpenContextDone,
                  weak_factory_.GetWeakPtr(),
-                 status_cb));
+                 bound_status_cb));
 }
 
 base::Time FFmpegDemuxer::GetTimelineOffset() const {
   return timeline_offset_;
 }
 
 DemuxerStream* FFmpegDemuxer::GetStream(DemuxerStream::Type type) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   return GetFFmpegStream(type);
 }
@@ skipping 578 matching lines @@
 
 void FFmpegDemuxer::SetLiveness(DemuxerStream::Liveness liveness) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   for (const auto& stream : streams_) {  // |stream| is a ref to a pointer.
     if (stream)
       stream->SetLiveness(liveness);
   }
 }
 
 }  // namespace media