[ARC] [Split this CL] Convert ios/web/webui to ARC.

ios/web/webui/url_data_source_ios.mm

 // 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.
 
 #include "ios/web/public/url_data_source_ios.h"
 
 #include "ios/web/public/web_client.h"
 #include "ios/web/webui/url_data_manager_ios.h"
 #include "net/url_request/url_request.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace web {
 
 void URLDataSourceIOS::Add(BrowserState* browser_state,
                            URLDataSourceIOS* source) {
   URLDataManagerIOS::AddDataSource(browser_state, source);
 }
 
 bool URLDataSourceIOS::ShouldReplaceExistingSource() const {
   return true;
 }
@@ skipping 11 matching lines @@
 }
 
 bool URLDataSourceIOS::ShouldServiceRequest(
     const net::URLRequest* request) const {
   if (GetWebClient()->IsAppSpecificURL(request->url()))
     return true;
   return false;
 }
 
 }  // namespace web