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

ios/web/webui/url_fetcher_block_adapter.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_WEB_WEBUI_URL_FETCHER_BLOCK_ADAPTER_H_
 #define IOS_WEB_WEBUI_URL_FETCHER_BLOCK_ADAPTER_H_
 
 #import <Foundation/Foundation.h>
 
+#include <memory>
+
 #include "base/mac/scoped_block.h"
-#include "base/memory/scoped_ptr.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "url/gurl.h"
 
 namespace net {
 class URLFetcher;
 class URLRequestContextGetter;
 }  // namespace net
 
 namespace web {
 
@@ skipping 23 matching lines @@
 
  private:
   // The URL to fetch.
   const GURL url_;
   // The request context.
   net::URLRequestContextGetter* request_context_;
   // Callback for resource load.
   base::mac::ScopedBlock<web::URLFetcherBlockAdapterCompletion>
       completion_handler_;
   // URLFetcher for retrieving data from net stack.
-  scoped_ptr<net::URLFetcher> fetcher_;
+  std::unique_ptr<net::URLFetcher> fetcher_;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_WEBUI_URL_FETCHER_BLOCK_ADAPTER_H_