Convert //ios from scoped_ptr to std::unique_ptr.

ios/net/http_response_headers_util.h

 // 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.
 
 #ifndef IOS_NET_HTTP_RESPONSE_HEADERS_UTIL_H_
 #define IOS_NET_HTTP_RESPONSE_HEADERS_UTIL_H_
 
-#include "base/memory/scoped_ptr.h"
 #include "net/http/http_response_headers.h"
 
 @class NSHTTPURLResponse;
 
 namespace net {
 
 // Placeholder status description since the actual text from the headers is not
 // available.
 extern const std::string kDummyHttpStatusDescription;
 
 // Constructs a net::HttpResponseHeaders from |response|.
 // Note: The HTTP version and the status code description are not accessible
 // from NSHTTPURLResponse, so HTTP/1.0 and kDummyHttpStatusDescription will
 // be used in the status line instead.
 scoped_refptr<HttpResponseHeaders> CreateHeadersFromNSHTTPURLResponse(
     NSHTTPURLResponse* response);
 
 }  // namespace net
 
 #endif  // IOS_NET_HTTP_RESPONSE_HEADERS_UTIL_H_