Remove ImageSkia::empty and ImageSkia::extractSubset

ui/views/controls/button/image_button.cc

 // 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.
 
 #include "ui/views/controls/button/image_button.h"
 
 #include "base/utf_string_conversions.h"
 #include "ui/base/animation/throb_animation.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image_skia_operations.h"
@@ skipping 79 matching lines @@
     if (v_alignment_ == ALIGN_MIDDLE)
       y = (height() - img.height()) / 2;
     else if (v_alignment_ == ALIGN_BOTTOM)
       y = height() - img.height();
 
     if (!background_image_.isNull())
       canvas->DrawImageInt(background_image_, x, y);
 
     canvas->DrawImageInt(img, x, y);
 
-    if (!overlay_image_.empty())
+    if (!overlay_image_.isNull())
       canvas->DrawImageInt(overlay_image_, x, y);
   }
   OnPaintFocusBorder(canvas);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ImageButton, protected:
 
 gfx::ImageSkia ImageButton::GetImageToPaint() {
   gfx::ImageSkia img;
@@ skipping 68 matching lines @@
 bool ToggleImageButton::GetTooltipText(const gfx::Point& p,
                                        string16* tooltip) const {
   if (!toggled_ || toggled_tooltip_text_.empty())
     return Button::GetTooltipText(p, tooltip);
 
   *tooltip = toggled_tooltip_text_;
   return true;
 }
 
 }  // namespace views