Revert changes from r152523 and split bitstream converter creation and enabling.

media/filters/gpu_video_decoder.cc

Index: media/filters/gpu_video_decoder.cc
diff --git a/media/filters/gpu_video_decoder.cc b/media/filters/gpu_video_decoder.cc
index 27b6aabb8d1eab8e795ab1cb3e7a285297965953..40af5a3b777904ce9d179dca9dfa5d7eb019ec19 100644
--- a/media/filters/gpu_video_decoder.cc
+++ b/media/filters/gpu_video_decoder.cc
@@ -115,18 +115,7 @@ void GpuVideoDecoder::Stop(const base::Closure& closure) {
 void GpuVideoDecoder::Initialize(const scoped_refptr<DemuxerStream>& stream,
                                  const PipelineStatusCB& orig_status_cb,
                                  const StatisticsCB& statistics_cb) {
-  const VideoDecoderConfig& config = stream->video_decoder_config();
   if (!gvd_loop_proxy_) {
-    // FFmpegDemuxer's destructor frees/clears the AVStream underpinnings of
-    // FFmpegDemuxerStream without notifying the stream, creating a race between
-    // initialization and teardown.  As a HACK until this is fixed, enable
-    // the bitstream converter before posting the Initialize() call to the video
-    // decoder thread since we know the DemuxerStream is valid at this point.
-    // See http://crbug.com/143460 for more detail.
-    // TODO(fischman): drop this hack!
-    if (config.IsValidConfig() && config.codec() == kCodecH264)
-      stream->EnableBitstreamConverter();
-
     gvd_loop_proxy_ = base::ResetAndReturn(&message_loop_factory_cb_).Run();
     gvd_loop_proxy_->PostTask(FROM_HERE, base::Bind(
         &GpuVideoDecoder::Initialize,
@@ -146,6 +135,7 @@ void GpuVideoDecoder::Initialize(const scoped_refptr<DemuxerStream>& stream,
 
   // TODO(scherkus): this check should go in Pipeline prior to creating
   // decoder objects.
+  const VideoDecoderConfig& config = stream->video_decoder_config();
   if (!config.IsValidConfig()) {
     DLOG(ERROR) << "Invalid video stream - " << config.AsHumanReadableString();
     status_cb.Run(PIPELINE_ERROR_DECODE);
@@ -159,6 +149,9 @@ void GpuVideoDecoder::Initialize(const scoped_refptr<DemuxerStream>& stream,
     return;
   }
 
+  if (config.codec() == kCodecH264)
+    stream->EnableBitstreamConverter();
+
   demuxer_stream_ = stream;
   statistics_cb_ = statistics_cb;