Remove locking from FFmpegDemuxerStream and associated TODOs from media code.

media/filters/ffmpeg_video_decoder.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_video_decoder.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 233 matching lines @@
 
   read_cb_ = read_cb;
   ReadFromDemuxerStream();
 }
 
 void FFmpegVideoDecoder::ReadFromDemuxerStream() {
   DCHECK_NE(state_, kUninitialized);
   DCHECK_NE(state_, kDecodeFinished);
   DCHECK(!read_cb_.is_null());
 
-  demuxer_stream_->Read(base::Bind(&FFmpegVideoDecoder::DecryptOrDecodeBuffer,
-                                   this));
-}
-
-void FFmpegVideoDecoder::DecryptOrDecodeBuffer(
-    DemuxerStream::Status status,
-    const scoped_refptr<DecoderBuffer>& buffer) {
-  DCHECK_EQ(status != DemuxerStream::kOk, !buffer) << status;
-  // TODO(scherkus): fix FFmpegDemuxerStream::Read() to not execute our read
-  // callback on the same execution stack so we can get rid of forced task post.
-  message_loop_->PostTask(FROM_HERE, base::Bind(
-      &FFmpegVideoDecoder::DoDecryptOrDecodeBuffer, this, status, buffer));
+  demuxer_stream_->Read(base::Bind(
+      &FFmpegVideoDecoder::DoDecryptOrDecodeBuffer, this));
 }
 
 void FFmpegVideoDecoder::DoDecryptOrDecodeBuffer(
     DemuxerStream::Status status,
     const scoped_refptr<DecoderBuffer>& buffer) {
-  DCHECK(message_loop_->BelongsToCurrentThread());
+  if (!message_loop_->BelongsToCurrentThread()) {
+    message_loop_->PostTask(FROM_HERE, base::Bind(
+        &FFmpegVideoDecoder::DoDecryptOrDecodeBuffer, this, status, buffer));
+    return;
+  }
+
   DCHECK_NE(state_, kDecodeFinished);
+  DCHECK_EQ(status != DemuxerStream::kOk, !buffer) << status;
 
   if (state_ == kUninitialized)
     return;
 
   DCHECK(!read_cb_.is_null());
 
   if (!reset_cb_.is_null()) {
     base::ResetAndReturn(&read_cb_).Run(kOk, NULL);
     DoReset();
     return;
@@ skipping 244 matching lines @@
   if (!codec || avcodec_open2(codec_context_, codec, NULL) < 0) {
     ReleaseFFmpegResources();
     return false;
   }
 
   av_frame_ = avcodec_alloc_frame();
   return true;
 }
 
 }  // namespace media