Adjust URLFetcher::Create API so that object is returned as scoped_ptr.

ios/chrome/browser/updatable_config/updatable_config_base.mm

 // Copyright 2013 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.
 
 #import "ios/chrome/browser/updatable_config/updatable_config_base.h"
 
 #include "base/logging.h"
 #import "base/mac/bind_objc_block.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted.h"
@@ skipping 39 matching lines @@
 // Class to fetch config update |url| and also act as the delegate to
 // handle callbacks from URLFetcher.
 class ConfigFetcher : public net::URLFetcherDelegate {
  public:
   ConfigFetcher(UpdatableConfigBase* owner,
                 id<UpdatableResourceDescriptorBridge> descriptor)
       : owner_(owner), descriptor_(descriptor) {}
 
   // Starts fetching |url| for updated configuration.
   void Fetch(const GURL& url, net::URLRequestContextGetter* context) {
-    fetcher_.reset(net::URLFetcher::Create(url, net::URLFetcher::GET, this));
+    fetcher_ = net::URLFetcher::Create(url, net::URLFetcher::GET, this);
     fetcher_->SetRequestContext(context);
     fetcher_->Start();
   }
 
   void OnURLFetchComplete(const net::URLFetcher* fetcher) override {
     DCHECK_EQ(fetcher_, fetcher);
     NSData* responseData = nil;
     if (fetcher_->GetResponseCode() == net::HTTP_OK) {
       std::string response;
       fetcher_->GetResponseAsString(&response);
@@ skipping 186 matching lines @@
     return;
   if (!_configFetcher) {
     _configFetcher.reset(
         new ConfigFetcher(self, [_updatableResource descriptor]));
   }
   GURL url = net::GURLWithNSURL([[_updatableResource descriptor] updateURL]);
   _configFetcher->Fetch(url, _requestContextGetter.get());
 }
 
 @end