Pass the ImageSkia by pointer instead of by reference, which will create shallow copy.

ui/gfx/image/image_skia.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_skia.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 
@@ skipping 205 matching lines @@
 }
 
 ImageSkia& ImageSkia::operator=(const ImageSkia& other) {
   storage_ = other.storage_;
   return *this;
 }
 
 ImageSkia::~ImageSkia() {
 }
 
-ImageSkia ImageSkia::DeepCopy() const {
-  ImageSkia copy;
+scoped_ptr<ImageSkia> ImageSkia::DeepCopy() const {
+  ImageSkia* copy = new ImageSkia;
   if (isNull())
-    return copy;
+    return scoped_ptr<ImageSkia>(copy);
 
   CHECK(CanRead());
 
   std::vector<gfx::ImageSkiaRep>& reps = storage_->image_reps();
   for (std::vector<gfx::ImageSkiaRep>::iterator iter = reps.begin();
        iter != reps.end(); ++iter) {
-    copy.AddRepresentation(*iter);
+    copy->AddRepresentation(*iter);
   }
   // The copy has its own storage. Detach the copy from the current
   // thread so that other thread can use this.
-  if (!copy.isNull())
-    copy.storage_->DetachFromThread();
-  return copy;
+  if (!copy->isNull())
+    copy->storage_->DetachFromThread();
+  return scoped_ptr<ImageSkia>(copy);
 }
 
 bool ImageSkia::BackedBySameObjectAs(const gfx::ImageSkia& other) const {
   return storage_.get() == other.storage_.get();
 }
 
 void ImageSkia::AddRepresentation(const ImageSkiaRep& image_rep) {
   DCHECK(!image_rep.is_null());
 
   // TODO(oshima): This method should be called |SetRepresentation|
@@ skipping 148 matching lines @@
 bool ImageSkia::CanModify() const {
   return !storage_ || storage_->CanModify();
 }
 
 void ImageSkia::DetachStorageFromThread() {
   if (storage_)
     storage_->DetachFromThread();
 }
 
 }  // namespace gfx