Support for showing/hiding status area volume controls in desktop devices

chrome/browser/chromeos/system_key_event_listener.h

Index: chrome/browser/chromeos/system_key_event_listener.h
===================================================================
--- chrome/browser/chromeos/system_key_event_listener.h	(revision 119932)
+++ chrome/browser/chromeos/system_key_event_listener.h	(working copy)
@@ -28,7 +28,12 @@
   class CapsLockObserver {
    public:
     virtual void OnCapsLockChange(bool enabled) = 0;
+   protected:
+    CapsLockObserver() {}
+    virtual ~CapsLockObserver() {}
+    DISALLOW_COPY_AND_ASSIGN(CapsLockObserver);
   };
+
   static void Initialize();
   static void Shutdown();
   // GetInstance returns NULL if not initialized or if already shutdown.
@@ -48,8 +53,6 @@
   SystemKeyEventListener();
   virtual ~SystemKeyEventListener();
 
-  AudioHandler* GetAudioHandler() const;
-
 #if defined(TOOLKIT_USES_GTK)
   // This event filter intercepts events before they reach GDK, allowing us to
   // check for system level keyboard events regardless of which window has