chromeos-events: Remove SystemKeyEventListener::ModifierObservers.

chrome/browser/chromeos/events/system_key_event_listener.h

Index: chrome/browser/chromeos/events/system_key_event_listener.h
diff --git a/chrome/browser/chromeos/events/system_key_event_listener.h b/chrome/browser/chromeos/events/system_key_event_listener.h
index b76ea8ee2574fe36eed54d7d879ed55d2fec8409..8f994fada6e57d76fa96574cb0709ddb9c0502da 100644
--- a/chrome/browser/chromeos/events/system_key_event_listener.h
+++ b/chrome/browser/chromeos/events/system_key_event_listener.h
@@ -26,26 +26,6 @@ class SystemKeyEventListener : public base::MessageLoopForUI::Observer {
     DISALLOW_COPY_AND_ASSIGN(CapsLockObserver);
   };
 
-  // Observer for modifier keys' state changes.
-  class ModifiersObserver {
-   public:
-    enum {
-      SHIFT_PRESSED = 1,
-      CTRL_PRESSED = 1 << 1,
-      ALT_PRESSED = 1 << 2,
-    };
-
-    // |pressed_modifiers| is a bitmask of SHIFT_PRESSED, CTRL_PRESSED and
-    // ALT_PRESSED.
-    virtual void OnModifiersChange(int pressed_modifiers) = 0;
-
-   protected:
-    ModifiersObserver() {}
-    virtual ~ModifiersObserver() {}
-
-    DISALLOW_COPY_AND_ASSIGN(ModifiersObserver);
-  };
-
   static void Initialize();
   static void Shutdown();
   // GetInstance returns NULL if not initialized or if already shutdown.
@@ -54,9 +34,7 @@ class SystemKeyEventListener : public base::MessageLoopForUI::Observer {
   void Stop();
 
   void AddCapsLockObserver(CapsLockObserver* observer);
-  void AddModifiersObserver(ModifiersObserver* observer);
   void RemoveCapsLockObserver(CapsLockObserver* observer);
-  void RemoveModifiersObserver(ModifiersObserver* observer);
 
  private:
   // Defines the delete on exit Singleton traits we like.  Best to have this
@@ -82,9 +60,7 @@ class SystemKeyEventListener : public base::MessageLoopForUI::Observer {
 
   unsigned int num_lock_mask_;
   bool caps_lock_is_on_;
-  int pressed_modifiers_;
   ObserverList<CapsLockObserver> caps_lock_observers_;
-  ObserverList<ModifiersObserver> modifiers_observers_;
 
   // Base X ID for events from the XKB extension.
   int xkb_event_base_;