views: Convert IsFocusable() to just focusable() since it's just a simple accessor.

ui/views/controls/button/custom_button.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_
 #pragma once
 
 #include "ui/base/animation/animation_delegate.h"
 #include "ui/views/controls/button/button.h"
@@ skipping 100 matching lines @@
 
   // Returns true if the button should become pressed when the user
   // holds the mouse down over the button. For this implementation,
   // we simply return IsTriggerableEvent(event).
   virtual bool ShouldEnterPushedState(const MouseEvent& event);
 
   // Overridden from View:
   virtual void ViewHierarchyChanged(bool is_add,
                                     View* parent,
                                     View* child) OVERRIDE;
-  virtual bool IsFocusable() const OVERRIDE;
   virtual void OnBlur() OVERRIDE;
 
   // The button state (defined in implementation)
   ButtonState state_;
 
   // Hover animation.
   scoped_ptr<ui::ThrobAnimation> hover_animation_;
 
  private:
   // Should we animate when the state changes? Defaults to true.
   bool animate_on_state_change_;
 
   // Is the hover animation running because StartThrob was invoked?
   bool is_throbbing_;
 
   // Mouse event flags which can trigger button actions.
   int triggerable_event_flags_;
 
   // See description above setter.
   bool request_focus_on_press_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_