Fix memory leak in ImageButton exposed by r20028.

views/controls/button/image_button.h

 // Copyright (c) 2006-2008 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 VIEWS_CONTROLS_BUTTON_IMAGE_BUTTON_H_
 #define VIEWS_CONTROLS_BUTTON_IMAGE_BUTTON_H_
 
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "views/controls/button/custom_button.h"
 
@@ skipping 29 matching lines @@
 
  protected:
   // Returns the image to paint. This is invoked from paint and returns a value
   // from images.
   virtual SkBitmap GetImageToPaint();
 
   // The images used to render the different states of this button.
   SkBitmap images_[BS_COUNT];
 
   // The background image.
-  SkBitmap* background_image_;
+  scoped_ptr<SkBitmap> background_image_;
 
  private:
   // Image alignment.
   HorizontalAlignment h_alignment_;
   VerticalAlignment v_alignment_;
 
   DISALLOW_COPY_AND_ASSIGN(ImageButton);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 37 matching lines @@
   // The parent class's tooltip_text_ is displayed when not toggled, and
   // this one is shown when toggled.
   std::wstring toggled_tooltip_text_;
 
   DISALLOW_EVIL_CONSTRUCTORS(ToggleImageButton);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_BUTTON_IMAGE_BUTTON_H_