Add support for multi resolution icons

ui/gfx/image_mac.mm

 // Copyright (c) 2011 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.
 
 #import <AppKit/AppKit.h>
 
+#include "base/memory/scoped_ptr.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 
 namespace gfx {
 namespace internal {
 
-const SkBitmap* NSImageToSkBitmap(NSImage* image) {
-  return new SkBitmap(::gfx::NSImageToSkBitmap(image, [image size], false));
+bool NSImageToSkBitmaps(NSImage* image, std::vector<const SkBitmap*>& bitmaps) {
+  for (NSImageRep* imageRep in [image representations]) {
+    scoped_ptr<SkBitmap> bitmap(new SkBitmap(
+        gfx::NSImageRepToSkBitmap(imageRep, [imageRep size], false)));
+    if (bitmap->isNull())
+      return false;
+    bitmaps.push_back(bitmap.release());
+  }
+  return true;
 }
 
 }  // namespace internal
 }  // namespace gfx