Use enum instead of string in MessageLoopFactory::GetMessageLoop*

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"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
-#include "base/message_loop.h"
+#include "base/location.h"
+#include "base/message_loop_proxy.h"
 #include "base/string_number_conversions.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/limits.h"
 #include "media/base/media_switches.h"
 #include "media/base/pipeline.h"
 #include "media/base/video_decoder_config.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 #include "media/ffmpeg/ffmpeg_common.h"
@@ skipping 22 matching lines @@
   const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
   std::string threads(cmd_line->GetSwitchValueASCII(switches::kVideoThreads));
   if (threads.empty() || !base::StringToInt(threads, &decode_threads))
     return decode_threads;
 
   decode_threads = std::max(decode_threads, 0);
   decode_threads = std::min(decode_threads, kMaxDecodeThreads);
   return decode_threads;
 }
 
-FFmpegVideoDecoder::FFmpegVideoDecoder(
-    const base::Callback<MessageLoop*()>& message_loop_cb,
-    Decryptor* decryptor)
+FFmpegVideoDecoder::FFmpegVideoDecoder(const MessageLoopCB& message_loop_cb,
+                                       Decryptor* decryptor)
     : message_loop_factory_cb_(message_loop_cb),
       message_loop_(NULL),
       state_(kUninitialized),
       codec_context_(NULL),
       av_frame_(NULL),
       decryptor_(decryptor) {
 }
 
 int FFmpegVideoDecoder::GetVideoBuffer(AVCodecContext* codec_context,
                                        AVFrame* frame) {
@@ skipping 63 matching lines @@
   frame->opaque = NULL;
 }
 
 void FFmpegVideoDecoder::Initialize(const scoped_refptr<DemuxerStream>& stream,
                                     const PipelineStatusCB& status_cb,
                                     const StatisticsCB& statistics_cb) {
   // Ensure FFmpeg has been initialized
   FFmpegGlue::GetInstance();
 
   if (!message_loop_) {
-    message_loop_ = message_loop_factory_cb_.Run();
-    message_loop_factory_cb_.Reset();
-
+    message_loop_ = base::ResetAndReturn(&message_loop_factory_cb_).Run();
     message_loop_->PostTask(FROM_HERE, base::Bind(
         &FFmpegVideoDecoder::Initialize, this,
         stream, status_cb, statistics_cb));
     return;
   }
 
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
+  DCHECK(message_loop_->BelongsToCurrentThread());
   DCHECK(!demuxer_stream_);
 
   if (!stream) {
     status_cb.Run(PIPELINE_ERROR_DECODE);
     return;
   }
 
   demuxer_stream_ = stream;
   statistics_cb_ = statistics_cb;
 
@@ skipping 39 matching lines @@
 }
 
 void FFmpegVideoDecoder::Read(const ReadCB& read_cb) {
   // Complete operation asynchronously on different stack of execution as per
   // the API contract of VideoDecoder::Read()
   message_loop_->PostTask(FROM_HERE, base::Bind(
       &FFmpegVideoDecoder::DoRead, this, read_cb));
 }
 
 void FFmpegVideoDecoder::Reset(const base::Closure& closure) {
-  if (MessageLoop::current() != message_loop_) {
+  if (!message_loop_->BelongsToCurrentThread()) {
     message_loop_->PostTask(FROM_HERE, base::Bind(
         &FFmpegVideoDecoder::Reset, this, closure));
     return;
   }
 
   reset_cb_ = closure;
 
   // Defer the reset if a read is pending.
   if (!read_cb_.is_null())
     return;
 
   DoReset();
 }
 
 void FFmpegVideoDecoder::DoReset() {
   DCHECK(read_cb_.is_null());
 
   avcodec_flush_buffers(codec_context_);
   state_ = kNormal;
   reset_cb_.Run();
   reset_cb_.Reset();
 }
 
 void FFmpegVideoDecoder::Stop(const base::Closure& closure) {
-  if (MessageLoop::current() != message_loop_) {
+  if (!message_loop_->BelongsToCurrentThread()) {
     message_loop_->PostTask(FROM_HERE, base::Bind(
         &FFmpegVideoDecoder::Stop, this, closure));
     return;
   }
 
   if (decryptor_)
     decryptor_->Stop();
 
   stop_cb_ = closure;
 
   // Defer stopping if a read is pending.
   if (!read_cb_.is_null())
     return;
 
   DoStop();
 }
 
 void FFmpegVideoDecoder::DoStop() {
   ReleaseFFmpegResources();
   state_ = kUninitialized;
   base::ResetAndReturn(&stop_cb_).Run();
 }
 
 FFmpegVideoDecoder::~FFmpegVideoDecoder() {
   ReleaseFFmpegResources();
 }
 
 void FFmpegVideoDecoder::DoRead(const ReadCB& read_cb) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
+  DCHECK(message_loop_->BelongsToCurrentThread());
   DCHECK(!read_cb.is_null());
   CHECK(read_cb_.is_null()) << "Overlapping decodes are not supported.";
 
   // This can happen during shutdown after Stop() has been called.
   if (state_ == kUninitialized) {
     return;
   }
 
   // Return empty frames if decoding has finished.
   if (state_ == kDecodeFinished) {
@@ skipping 21 matching lines @@
   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));
 }
 
 void FFmpegVideoDecoder::DoDecryptOrDecodeBuffer(
     DemuxerStream::Status status,
     const scoped_refptr<DecoderBuffer>& buffer) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
+  DCHECK(message_loop_->BelongsToCurrentThread());
   DCHECK_NE(state_, kUninitialized);
   DCHECK_NE(state_, kDecodeFinished);
   DCHECK(!read_cb_.is_null());
 
   if (!stop_cb_.is_null()) {
     base::ResetAndReturn(&read_cb_).Run(kOk, NULL);
     DoStop();
     return;
   }
 
@@ skipping 24 matching lines @@
 void FFmpegVideoDecoder::BufferDecrypted(
     Decryptor::Status decrypt_status,
     const scoped_refptr<DecoderBuffer>& buffer) {
   message_loop_->PostTask(FROM_HERE, base::Bind(
       &FFmpegVideoDecoder::DoBufferDecrypted, this, decrypt_status, buffer));
 }
 
 void FFmpegVideoDecoder::DoBufferDecrypted(
     Decryptor::Status decrypt_status,
     const scoped_refptr<DecoderBuffer>& buffer) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
+  DCHECK(message_loop_->BelongsToCurrentThread());
   DCHECK_NE(state_, kUninitialized);
   DCHECK_NE(state_, kDecodeFinished);
   DCHECK(!read_cb_.is_null());
 
   if (!reset_cb_.is_null()) {
     base::ResetAndReturn(&read_cb_).Run(kOk, NULL);
     DoReset();
     return;
   }
 
   if (decrypt_status == Decryptor::kNoKey ||
       decrypt_status == Decryptor::kError) {
     state_ = kDecodeFinished;
     base::ResetAndReturn(&read_cb_).Run(kDecryptError, NULL);
     return;
   }
 
   DCHECK_EQ(Decryptor::kSuccess, decrypt_status);
   DCHECK(buffer);
   DCHECK(buffer->GetDataSize());
   DCHECK(!buffer->GetDecryptConfig());
   DecodeBuffer(buffer);
 }
 
 void FFmpegVideoDecoder::DecodeBuffer(
     const scoped_refptr<DecoderBuffer>& buffer) {
-  DCHECK_EQ(MessageLoop::current(), message_loop_);
+  DCHECK(message_loop_->BelongsToCurrentThread());
   DCHECK_NE(state_, kUninitialized);
   DCHECK_NE(state_, kDecodeFinished);
   DCHECK(reset_cb_.is_null());
   DCHECK(!read_cb_.is_null());
   DCHECK(buffer);
 
   // During decode, because reads are issued asynchronously, it is possible to
   // receive multiple end of stream buffers since each read is acked. When the
   // first end of stream buffer is read, FFmpeg may still have frames queued
   // up in the decoder so we need to go through the decode loop until it stops
@@ skipping 129 matching lines @@
     av_free(codec_context_);
     codec_context_ = NULL;
   }
   if (av_frame_) {
     av_free(av_frame_);
     av_frame_ = NULL;
   }
 }
 
 }  // namespace media