Avoid double task trampoline for Pipeline state transitions.

media/filters/ffmpeg_demuxer.cc

Index: media/filters/ffmpeg_demuxer.cc
diff --git a/media/filters/ffmpeg_demuxer.cc b/media/filters/ffmpeg_demuxer.cc
index be31709b05017603df7c655e6e06e417eaef997e..b8adeae3f4364f1f7b081fcdba00a80198f1589e 100644
--- a/media/filters/ffmpeg_demuxer.cc
+++ b/media/filters/ffmpeg_demuxer.cc
@@ -693,6 +693,9 @@ void FFmpegDemuxer::Initialize(DemuxerHost* host,
   // 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(
@@ -701,7 +704,7 @@ void FFmpegDemuxer::Initialize(DemuxerHost* host,
       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 {