Resubmit 'Refactor the TrayAudio code so that it can be used by other platforms.'

chrome/browser/ui/ash/system_tray_delegate_chromeos.h

Index: chrome/browser/ui/ash/system_tray_delegate_chromeos.h
diff --git a/chrome/browser/ui/ash/system_tray_delegate_chromeos.h b/chrome/browser/ui/ash/system_tray_delegate_chromeos.h
index f465dd350195b3bdefac048e675b1a301021defa..ec6fb22bb507e92601e92834a4492ab6985ea082 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.h
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.h
@@ -20,6 +20,7 @@
 #include "chrome/browser/chromeos/events/system_key_event_listener.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/ash/system_tray_delegate_chromeos.h"
+#include "chromeos/audio/cras_audio_handler.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "chromeos/ime/input_method_manager.h"
 #include "chromeos/login/login_state.h"
@@ -38,6 +39,7 @@ class SystemTrayDelegateChromeOS
       public content::NotificationObserver,
       public input_method::InputMethodManager::Observer,
       public chromeos::LoginState::Observer,
+      public chromeos::CrasAudioHandler::AudioObserver,
       public device::BluetoothAdapter::Observer,
       public SystemKeyEventListener::CapsLockObserver,
       public policy::CloudPolicyStore::Observer,
@@ -186,6 +188,15 @@ class SystemTrayDelegateChromeOS
   virtual void InputMethodMenuItemChanged(
       ash::ime::InputMethodMenuManager* manager) OVERRIDE;
 
+  // Overridden from CrasAudioHandler::AudioObserver.
+  virtual void OnOutputVolumeChanged() OVERRIDE;
+  virtual void OnOutputMuteChanged() OVERRIDE;
+  virtual void OnInputGainChanged() OVERRIDE;
+  virtual void OnInputMuteChanged() OVERRIDE;
+  virtual void OnAudioNodesChanged() OVERRIDE;
+  virtual void OnActiveOutputNodeChanged() OVERRIDE;
+  virtual void OnActiveInputNodeChanged() OVERRIDE;
+
   // drive::JobListObserver overrides.
   virtual void OnJobAdded(const drive::JobInfo& job_info) OVERRIDE;