MD - update checkbox and radio buttons

ui/views/controls/button/label_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_LABEL_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 23 matching lines @@
   // Amount to inset each edge of the button when drawing the focus rectangle.
   static const int kFocusRectInset;
 
   static const char kViewClassName[];
 
   LabelButton(ButtonListener* listener, const base::string16& text);
   ~LabelButton() override;
 
   // Gets or sets the image shown for the specified button state.
   // GetImage returns the image for STATE_NORMAL if the state's image is empty.
-  virtual const gfx::ImageSkia& GetImage(ButtonState for_state);
+  virtual gfx::ImageSkia GetImage(ButtonState for_state) const;
   void SetImage(ButtonState for_state, const gfx::ImageSkia& image);
 
   // Gets or sets the text shown on the button.
   const base::string16& GetText() const;
   virtual void SetText(const base::string16& text);
 
   // Sets the text color shown for the specified button |for_state| to |color|.
   void SetTextColor(ButtonState for_state, SkColor color);
 
   // Sets the text colors shown for the non-disabled states to |color|.
@@ skipping 175 matching lines @@
   gfx::HorizontalAlignment horizontal_alignment_;
 
   std::unique_ptr<Painter> focus_painter_;
 
   DISALLOW_COPY_AND_ASSIGN(LabelButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_LABEL_BUTTON_H_