Pass task runners to AudioManager constructor.

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 e8a13a03881eade85aebfe139c293b58d3e7afb6..16373276b69dc1540a8b0292bcf66795ffeb5832 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -13,6 +13,7 @@
 #include "build/build_config.h"
 #include "content/browser/browser_process_sub_thread.h"
 #include "content/public/browser/browser_main_runner.h"
+#include "media/audio/audio_manager.h"
 
 namespace base {
 class CommandLine;
@@ -32,7 +33,6 @@ class ScopedIPCSupport;
 }
 
 namespace media {
-class AudioManager;
 #if defined(OS_WIN)
 class SystemMessageWindowWin;
 #elif defined(OS_LINUX) && defined(USE_UDEV)
@@ -249,7 +249,7 @@ class CONTENT_EXPORT BrowserMainLoop {
 
   // |user_input_monitor_| has to outlive |audio_manager_|, so declared first.
   scoped_ptr<media::UserInputMonitor> user_input_monitor_;
-  scoped_ptr<media::AudioManager> audio_manager_;
+  media::ScopedAudioManagerPtr audio_manager_;
 
   scoped_ptr<media::midi::MidiManager> midi_manager_;