Add old_state parameter to CustomButton::StateChanged

ui/views/controls/button/custom_button.h

 // Copyright (c) 2012 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_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 124 matching lines @@
   void OnBlur() override;
 
  protected:
   // Construct the Button with a Listener. See comment for Button's ctor.
   explicit CustomButton(ButtonListener* listener);
 
   // Invoked from SetState() when SetState() is passed a value that differs from
   // the current node_data. CustomButton's implementation of StateChanged() does
   // nothing; this method is provided for subclasses that wish to do something
   // on state changes.
-  virtual void StateChanged();
+  virtual void StateChanged(ButtonState old_state);
 
   // Returns true if the event is one that can trigger notifying the listener.
   // This implementation returns true if the left mouse button is down.
   virtual bool IsTriggerableEvent(const ui::Event& event);
 
   // 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 ui::Event& event);
 
@@ skipping 45 matching lines @@
 
   // The color of the ripple and hover.
   SkColor ink_drop_base_color_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_