JPEG decoding: replace ownership comments with std::unique_ptr.

ui/gfx/codec/jpeg_codec.cc

 // Copyright (c) 2011 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/codec/jpeg_codec.h"
 
 #include <setjmp.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 585 matching lines @@
     }
   }
 #endif
 
   jpeg_finish_decompress(&cinfo);
   jpeg_destroy_decompress(&cinfo);
   return true;
 }
 
 // static
-SkBitmap* JPEGCodec::Decode(const unsigned char* input, size_t input_size) {
+std::unique_ptr<SkBitmap> JPEGCodec::Decode(const unsigned char* input,
+                                            size_t input_size) {
   int w, h;
   std::vector<unsigned char> data_vector;
   if (!Decode(input, input_size, FORMAT_SkBitmap, &data_vector, &w, &h))
-    return NULL;
+    return nullptr;
 
   // Skia only handles 32 bit images.
   int data_length = w * h * 4;
 
-  SkBitmap* bitmap = new SkBitmap();
+  std::unique_ptr<SkBitmap> bitmap(new SkBitmap());
   bitmap->allocN32Pixels(w, h);
   memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length);
 
   return bitmap;
 }
 
 }  // namespace gfx