Add Stop() to AudioDecoder.

media/filters/audio_renderer_impl.cc

Index: media/filters/audio_renderer_impl.cc
diff --git a/media/filters/audio_renderer_impl.cc b/media/filters/audio_renderer_impl.cc
index f9b314d2ec2536ff43b18fd15ae2db222f61a4a0..00157a6b82b7b46fd8f857e4b9da3813da5befee 100644
--- a/media/filters/audio_renderer_impl.cc
+++ b/media/filters/audio_renderer_impl.cc
@@ -182,6 +182,29 @@ void AudioRendererImpl::ResetDecoderDone() {
   base::ResetAndReturn(&flush_cb_).Run();
 }
 
+void AudioRendererImpl::StopDecoder() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  decoder_->Stop(BindToCurrentLoop(
+      base::Bind(&AudioRendererImpl::StopDecoderDone, weak_this_)));
+}
+
+void AudioRendererImpl::StopDecoderDone() {
+  base::AutoLock auto_lock(lock_);

[DaleCurtis, 2014/01/08 00:30:54]

Previous method doesn't run this under lock.  It may be important not to do
that.

[rileya (GONE FROM CHROMIUM), 2014/01/08 21:05:50]

Which previous method do you mean?

[DaleCurtis, 2014/01/08 21:51:45]

See line 236 in Stop() below. callback.Run() occurs after releasing the lock_.

[rileya (GONE FROM CHROMIUM), 2014/01/08 22:02:55]

Ahh, gotcha. Looks like ResetDecoderDone also calls the reset callback before
releasing the lock, would changing both to call after releasing |lock_| be
reasonable?

[DaleCurtis, 2014/01/08 23:56:14]

sgtm

+  if (state_ == kStopped)
+    return;
+
+  DCHECK(!stop_cb_.is_null());
+
+  ChangeState_Locked(kStopped);
+  algorithm_.reset(NULL);

[DaleCurtis, 2014/01/08 00:30:54]

drop NULL.

+  init_cb_.Reset();
+  underflow_cb_.Reset();
+  time_cb_.Reset();
+  flush_cb_.Reset();

[xhwang, 2014/01/08 01:33:37]

Wrap 199-203 in a helper function so it can be shared here and on line 227?

[rileya (GONE FROM CHROMIUM), 2014/01/08 21:05:50]

StopDecoderDone was already basically this, so per Dale's suggestion on 226 I
just called it there.

+
+  base::ResetAndReturn(&stop_cb_).Run();
+}
+
 void AudioRendererImpl::Stop(const base::Closure& callback) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!callback.is_null());
@@ -194,6 +217,12 @@ void AudioRendererImpl::Stop(const base::Closure& callback) {
     sink_ = NULL;
   }
 
+  if (decoder_) {
+    stop_cb_ = callback;
+    StopDecoder();

[DaleCurtis, 2014/01/08 00:30:54]

You can probably drop the StopDecoder() method in favor of inlining it here.

[rileya (GONE FROM CHROMIUM), 2014/01/08 21:05:50]

Done.

+    return;
+  }
+
   {

[DaleCurtis, 2014/01/08 00:30:54]

Just call StopDecoderDone here?

[rileya (GONE FROM CHROMIUM), 2014/01/08 21:05:50]

Makes sense, done.

     base::AutoLock auto_lock(lock_);
     ChangeState_Locked(kStopped);