Move the device enumerate/open/close work to device thread from IO thread

content/browser/browser_main_loop.h

Index: content/browser/browser_main_loop.h
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index 69054315312aea4fd442b956435278ccf71c836a..9ecc61c6f63b01d520198c361ca5c5f00e27ad21 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -28,6 +28,10 @@ namespace media {
 class AudioManager;
 }
 
+namespace media_stream {
+class MediaStreamManager;
+}
+
 namespace net {
 class NetworkChangeNotifier;
 }
@@ -73,6 +77,7 @@ class BrowserMainLoop {
 
   // Can be called on any thread.
   static media::AudioManager* GetAudioManager();
+  static media_stream::MediaStreamManager* GetMediaStreamManager();
 
  private:
   // For ShutdownThreadsAndCleanUp.
@@ -96,6 +101,7 @@ class BrowserMainLoop {
   scoped_ptr<HighResolutionTimerManager> hi_res_timer_manager_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
   scoped_ptr<media::AudioManager> audio_manager_;
+  scoped_ptr<media_stream::MediaStreamManager> media_stream_manager_;
   // Per-process listener for online state changes.
   scoped_ptr<BrowserOnlineStateObserver> online_state_observer_;
 #if defined(OS_WIN)