AudioController to perform audio operations on a separate thread

Added AudioController as a wrapper over AudioOutputStream to operate methods of
AudioOutputStream on a separate thread managed by AudioController. This way most
of the audio operations will be non-blocking.

Next step is to modify AudioRendererHost to use AudioController.

TEST=media_unittests --gtest_filter=AudioControllerTest.*
BUG=39885

Review URL: http://codereview.chromium.org/2477005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49079 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 5 insertions, 3 deletions

diff --git a/chrome/browser/renderer_host/audio_renderer_host.cc b/chrome/browser/renderer_host/audio_renderer_host.cc
index 0fbc5e6..4d3226c 100644
--- a/chrome/browser/renderer_host/audio_renderer_host.cc
+++ b/chrome/browser/renderer_host/audio_renderer_host.cc
@@ -280,7 +280,7 @@ void AudioRendererHost::IPCAudioSource::Flush() {
   if (state_ != kPaused)
     return;
 
-  // The following operation is atomic in PushSource so we don't need to lock.
+  AutoLock auto_lock(lock_);
   push_source_.ClearAll();
 }
 
@@ -351,10 +351,12 @@ uint32 AudioRendererHost::IPCAudioSource::OnMoreData(AudioOutputStream* stream,
 
 void AudioRendererHost::IPCAudioSource::OnClose(AudioOutputStream* stream) {
   // Push source doesn't need to know the stream so just pass in NULL.
-  if (!shared_socket_.get())
+  if (!shared_socket_.get()) {
+    AutoLock auto_lock(lock_);
     push_source_.OnClose(NULL);
-  else
+  } else {
     shared_socket_->Close();
+  }
 }
 
 void AudioRendererHost::IPCAudioSource::OnError(AudioOutputStream* stream,