Add the button style for combobox

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 "base/memory/scoped_ptr.h"
 #include "ui/events/event_constants.h"
 #include "ui/gfx/animation/animation_delegate.h"
 #include "ui/views/controls/button/button.h"
 
 namespace gfx {
 class ThrobAnimation;
 }
 
 namespace views {
 
 class CustomButtonStateChangedDelegate;
 
 // A button with custom rendering. The common base class of ImageButton and
 // TextButton.
 // Note that this type of button is not focusable by default and will not be
 // part of the focus chain.  Call set_focusable(true) to make it part of the
 // focus chain.
 class VIEWS_EXPORT CustomButton : public Button,
                                   public gfx::AnimationDelegate {
  public:
+  // How long the hover animation takes if uninterrupted.
+  static const int kHoverFadeDurationMs;
+
   // The menu button's class name.
   static const char kViewClassName[];
 
   virtual ~CustomButton();
 
   // Get/sets the current display state of the button.
   ButtonState state() const { return state_; }
   void SetState(ButtonState state);
 
   // Starts throbbing. See HoverAnimation for a description of cycles_til_stop.
@@ skipping 110 matching lines @@
 protected:
   CustomButtonStateChangedDelegate() {}
 
 private:
   DISALLOW_COPY_AND_ASSIGN(CustomButtonStateChangedDelegate);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_