Change return type of FaviconTabHelper::GetFavicon() to gfx::Image.

ui/gfx/image/image.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/gfx/image/image.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 319 matching lines @@
     NSImage* image = NSImageFromImageSkia(*skia_rep->image());
     base::mac::NSObjectRetain(image);
     rep = new internal::ImageRepCocoa(image);
     CHECK(rep);
     AddRepresentation(rep);
   }
   return rep->AsImageRepCocoa()->image();
 }
 #endif
 
+SkBitmap Image::AsBitmap() const {
+  return IsEmpty() ? SkBitmap() : *ToSkBitmap();
+}
+
+ImageSkia Image::AsImageSkia() const {
+  return IsEmpty() ? ImageSkia(SkBitmap()) : *ToImageSkia();
+}
+
 ImageSkia* Image::CopyImageSkia() const {
   return new ImageSkia(*ToImageSkia());
 }
 
 SkBitmap* Image::CopySkBitmap() const {
   return new SkBitmap(*ToSkBitmap());
 }
 
 #if defined(TOOLKIT_GTK)
 GdkPixbuf* Image::CopyGdkPixbuf() const {
@@ skipping 55 matching lines @@
   }
   return it->second;
 }
 
 void Image::AddRepresentation(internal::ImageRep* rep) const {
   CHECK(storage_.get());
   storage_->representations().insert(std::make_pair(rep->type(), rep));
 }
 
 }  // namespace gfx