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

components/suggestions/image_encoder.h

 // Copyright 2014 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 COMPONENTS_SUGGESTIONS_IMAGE_ENCODER_H_
 #define COMPONENTS_SUGGESTIONS_IMAGE_ENCODER_H_
 
 #include <stddef.h>
+
+#include <memory>
 #include <vector>
 
 class SkBitmap;
 
 namespace suggestions {
 
-// From encoded bytes to SkBitmap. It's the caller's responsibility to delete
-// the bitmap.
-SkBitmap* DecodeJPEGToSkBitmap(const void* encoded_data, size_t size);
+// From encoded bytes to SkBitmap.
+std::unique_ptr<SkBitmap> DecodeJPEGToSkBitmap(const void* encoded_data,
+                                               size_t size);
 
-inline SkBitmap* DecodeJPEGToSkBitmap(
+inline std::unique_ptr<SkBitmap> DecodeJPEGToSkBitmap(
     const std::vector<unsigned char>& encoded_data) {
   return DecodeJPEGToSkBitmap(&encoded_data[0], encoded_data.size());
 }
 
 // From SkBitmap to a vector of JPEG-encoded bytes, |dst|.
 bool EncodeSkBitmapToJPEG(const SkBitmap& bitmap,
                           std::vector<unsigned char>* dest);
 
 }  // namespace suggestions
 
 #endif  // COMPONENTS_SUGGESTIONS_IMAGE_ENCODER_H_