Convert //chrome from scoped_ptr to std::unique_ptr

chrome/utility/safe_browsing/mac/dmg_iterator.cc

 // Copyright 2015 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 "chrome/utility/safe_browsing/mac/dmg_iterator.h"
 
 #include "chrome/utility/safe_browsing/mac/hfs.h"
 #include "chrome/utility/safe_browsing/mac/read_stream.h"
 
 namespace safe_browsing {
@@ skipping 57 matching lines @@
     hfs_.reset();
   }
 
   return false;
 }
 
 base::string16 DMGIterator::GetPath() {
   return hfs_->GetPath();
 }
 
-scoped_ptr<ReadStream> DMGIterator::GetReadStream() {
+std::unique_ptr<ReadStream> DMGIterator::GetReadStream() {
   return hfs_->GetReadStream();
 }
 
 }  // namespace dmg
 }  // namespace safe_browsing