Avoid crashing when an ImageSkia has no representations and is converted to SkBitmap.

ui/gfx/image/image_skia.h

 // 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.
 
 #ifndef UI_GFX_IMAGE_IMAGE_SKIA_H_
 #define UI_GFX_IMAGE_IMAGE_SKIA_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 95 matching lines @@
   // Wrapper function for SkBitmap::extractBitmap.
   // Deprecated, use ImageSkiaOperations::ExtractSubset instead.
   // TODO(pkotwicz): Remove this function.
   bool extractSubset(ImageSkia* dst, const SkIRect& subset) const;
 
   // Returns pointer to 1x bitmap contained by this object. If there is no 1x
   // bitmap, the bitmap whose scale factor is closest to 1x is returned.
   // This function should only be used in unittests and on platforms which do
   // not support scale factors other than 1x.
   // TODO(pkotwicz): Return null SkBitmap when the object has no 1x bitmap.
-  const SkBitmap* bitmap() const;
+  const SkBitmap* bitmap() const { return &operator SkBitmap&(); }
 
   // Returns a vector with the image reps contained in this object.
   // There is no guarantee that this will return all images rep for
   // supported scale factors.
   // TODO(oshima): Update all use of this API and make this to fail
   // when source is used.
   std::vector<gfx::ImageSkiaRep> image_reps() const;
 
  private:
   // Initialize ImageSkiaStorage with passed in parameters.
   // If the image rep's bitmap is empty, ImageStorage is set to NULL.
   void Init(const gfx::ImageSkiaRep& image_rep);
 
   // A refptr so that ImageRepSkia can be copied cheaply.
   scoped_refptr<internal::ImageSkiaStorage> storage_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_IMAGE_IMAGE_SKIA_H_