Add support for PNG representation in gfx::Image

ui/gfx/image/image_unittest_util.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.
 
 // Because the unit tests for gfx::Image are spread across multiple
 // implementation files, this header contains the reusable components.
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/layout.h"
 #include "ui/gfx/image/image_unittest_util.h"
@@ skipping 95 matching lines @@
 PlatformImage ToPlatformType(const gfx::Image& image) {
 #if defined(OS_MACOSX)
   return image.ToNSImage();
 #elif defined(TOOLKIT_GTK)
   return image.ToGdkPixbuf();
 #else
   return *image.ToSkBitmap();
 #endif
 }
 
+PlatformImage CopyPlatformType(const gfx::Image& image) {
+#if defined(OS_MACOSX)
+  return image.CopyNSImage();
+#elif defined(TOOLKIT_GTK)
+  return image.CopyGdkPixbuf();
+#else
+  return *image.ToSkBitmap();
+#endif
+}
+
 bool IsPlatformImageValid(PlatformImage image) {
 #if defined(OS_MACOSX) || defined(TOOLKIT_GTK)
   return image != NULL;
 #else
   return !image.isNull();
 #endif
 }
 
 bool PlatformImagesEqual(PlatformImage image1, PlatformImage image2) {
 #if defined(OS_MACOSX) || defined(TOOLKIT_GTK)
   return image1 == image2;
 #else
   return image1.getPixels() == image2.getPixels();
 #endif
 }
 
 }  // namespace test
 }  // namespace gfx