Add Stop() to AudioDecoder.

media/filters/ffmpeg_audio_decoder.cc

Index: media/filters/ffmpeg_audio_decoder.cc
diff --git a/media/filters/ffmpeg_audio_decoder.cc b/media/filters/ffmpeg_audio_decoder.cc
index a0e5889eff11aca7e6c84c6bdbf26080ca2fd8c0..7a8d55b8cc7714726a6705a423e0d33265f42eea 100644
--- a/media/filters/ffmpeg_audio_decoder.cc
+++ b/media/filters/ffmpeg_audio_decoder.cc
@@ -118,6 +118,12 @@ void FFmpegAudioDecoder::Read(const ReadCB& read_cb) {
 
   read_cb_ = BindToCurrentLoop(read_cb);
 
+  // Don't allow further reads after Stop().

[DaleCurtis, 2014/01/09 21:10:42]

Since the renderer / AudioBufferStream will invoke Stop(), I think you can just
DCHECK(stop_cb_.is_null()) here?

+  if (!stop_cb_.is_null()) {
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    return;
+  }
+
   // If we don't have any queued audio from the last packet we decoded, ask for
   // more data from the demuxer to satisfy this read.
   if (queued_audio_.empty()) {
@@ -155,12 +161,18 @@ void FFmpegAudioDecoder::Reset(const base::Closure& closure) {
   reset_cb.Run();
 }
 
-FFmpegAudioDecoder::~FFmpegAudioDecoder() {
-  // TODO(scherkus): should we require Stop() to be called? this might end up
-  // getting called on a random thread due to refcounting.
-  ReleaseFFmpegResources();
+void FFmpegAudioDecoder::Stop(const base::Closure& closure) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  stop_cb_ = BindToCurrentLoop(closure);
+
+  if (read_cb_.is_null()) {

[DaleCurtis, 2014/01/09 21:10:42]

{} is not necessary on single line conditionals.

+    DoStop();
+  }
+  // Otherwise a demuxer read is pending, we'll wait until it finishes.
 }
 
+FFmpegAudioDecoder::~FFmpegAudioDecoder() {}
+
 int FFmpegAudioDecoder::GetAudioBuffer(AVCodecContext* codec,
                                        AVFrame* frame,
                                        int flags) {
@@ -226,6 +238,15 @@ int FFmpegAudioDecoder::GetAudioBuffer(AVCodecContext* codec,
   return 0;
 }
 
+void FFmpegAudioDecoder::DoStop() {
+  DCHECK(!stop_cb_.is_null());
+
+  ResetTimestampState();
+  queued_audio_.clear();
+  ReleaseFFmpegResources();
+  base::ResetAndReturn(&stop_cb_).Run();
+}
+
 void FFmpegAudioDecoder::ReadFromDemuxerStream() {
   DCHECK(!read_cb_.is_null());
   demuxer_stream_->Read(base::Bind(
@@ -240,6 +261,14 @@ void FFmpegAudioDecoder::BufferReady(
   DCHECK(queued_audio_.empty());
   DCHECK_EQ(status != DemuxerStream::kOk, !input.get()) << status;
 
+  // Stop() is pending, we'll ignore the buffer we just got, fire read_cb_, and
+  // complete the Stop.
+  if (!stop_cb_.is_null()) {
+    base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);
+    DoStop();
+    return;
+  }
+
   if (status == DemuxerStream::kAborted) {
     DCHECK(!input.get());
     base::ResetAndReturn(&read_cb_).Run(kAborted, NULL);