Fall back to the default favicon on invalid favicon files.

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 324 matching lines @@
   }
   return rep->AsImageRepCocoa()->image();
 }
 #endif
 
 SkBitmap Image::AsBitmap() const {
   return IsEmpty() ? SkBitmap() : *ToSkBitmap();
 }
 
 ImageSkia Image::AsImageSkia() const {
-  return IsEmpty() ? ImageSkia(SkBitmap()) : *ToImageSkia();
+  return IsEmpty() ? ImageSkia() : *ToImageSkia();
 }
 
+#if defined(OS_MACOSX)
+NSImage* Image::AsNSImage() const {
+  return IsEmpty() ? nil : ToNSImage();
+}
+#endif
+
 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