Share one thread between all AudioOutputControllers instead of creating one per stream.

media/audio/linux/audio_manager_linux.h

Index: media/audio/linux/audio_manager_linux.h
diff --git a/media/audio/linux/audio_manager_linux.h b/media/audio/linux/audio_manager_linux.h
index ea335f0de622564d267e2dd432bd1fb137399b09..2703eed5708638d0598c07b26f900ae64fa61d63 100644
--- a/media/audio/linux/audio_manager_linux.h
+++ b/media/audio/linux/audio_manager_linux.h
@@ -11,12 +11,12 @@
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
 #include "base/thread.h"
-#include "media/audio/audio_io.h"
+#include "media/audio/audio_manager_base.h"
 
 class AlsaPcmOutputStream;
 class AlsaWrapper;
 
-class AudioManagerLinux : public AudioManager {
+class AudioManagerLinux : public AudioManagerBase {
  public:
   AudioManagerLinux();
 
@@ -44,17 +44,12 @@ class AudioManagerLinux : public AudioManager {
   virtual ~AudioManagerLinux();
 
  private:
-  // Thread used to interact with AudioOutputStreams created by this
-  // audio manger.
-  base::Thread audio_thread_;
   scoped_ptr<AlsaWrapper> wrapper_;
 
   Lock lock_;
   std::map<AlsaPcmOutputStream*, scoped_refptr<AlsaPcmOutputStream> >
       active_streams_;
 
-  bool initialized_;
-
   DISALLOW_COPY_AND_ASSIGN(AudioManagerLinux);
 };