MacViews: Style BUTTON_STYLE buttons using the "modern" UI

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/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/events/event_constants.h"
 #include "ui/gfx/animation/animation_delegate.h"
 #include "ui/gfx/animation/throb_animation.h"
 #include "ui/views/animation/ink_drop_state.h"
 #include "ui/views/controls/button/button.h"
 
 namespace views {
 
 class InkDropDelegate;
+class LabelButton;
 
 // A button with custom rendering. The base of ImageButton and LabelButton.
 // Note that this type of button is not focusable by default and will not be
 // part of the focus chain.  Call SetFocusable(true) to make it part of the
 // focus chain.
 class VIEWS_EXPORT CustomButton : public Button, public gfx::AnimationDelegate {
  public:
   // An enum describing the events on which a button should notify its listener.
   enum NotifyAction {
     NOTIFY_ON_PRESS,
     NOTIFY_ON_RELEASE,
   };
 
   // The menu button's class name.
   static const char kViewClassName[];
 
   static const CustomButton* AsCustomButton(const views::View* view);
   static CustomButton* AsCustomButton(views::View* view);
+  static const LabelButton* AsLabelButton(const views::View* view);

[sky, 2016/04/07 17:16:31]

I am not a fan of using the view class name for RTTI. It's brittle. Is there
another way to accomplish what you need that doesn't involve using the class
name?

[tapted, 2016/04/08 08:35:33]

There's not really any logic that depends on the RTTI - it's more just to be
defensive. So I've removed it in the latest CL. Currently this means that code
needs to be "careful" only to put the result of
PlatformStyle::CreateLabelButtonBorder onto a LabelButton.

We could make this agreement more formal by storing a LabelButton* data member
on LabelButtonBorder and ignoring (or DCHECKing) the |view| passed in via
Border::Paint into DialogButtonBorderMac

+  static LabelButton* AsLabelButton(views::View* view);
 
   ~CustomButton() override;
 
   // 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.
   void StartThrobbing(int cycles_til_stop);
 
@@ skipping 153 matching lines @@
   // because it needs to paint to a layer so it can extend beyond the bounds of
   // |this|.
   views::View* md_focus_ring_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_