Remove BrowserThread::UnsafeGetMessageLoopForThread()

ios/web/webui/url_data_manager_ios_backend.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/webui/url_data_manager_ios_backend.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 446 matching lines @@
       source->source()->GetContentSecurityPolicyObjectSrc());
   job->set_content_security_policy_frame_source("frame-src 'none';");
   job->set_deny_xframe_options(source->source()->ShouldDenyXFrameOptions());
   job->set_send_content_type_header(false);
 
   // Forward along the request to the data source.
   // URLRequestChromeJob should receive mime type before data. This
   // is guaranteed because request for mime type is placed in the
   // message loop before request for data. And correspondingly their
   // replies are put on the IO thread in the same order.
-  base::MessageLoop* target_message_loop =
-      web::WebThread::UnsafeGetMessageLoopForThread(web::WebThread::UI);
-  target_message_loop->task_runner()->PostTask(
+  scoped_refptr<base::SingleThreadTaskRunner> target_runner =
+      web::WebThread::GetTaskRunnerForThread(web::WebThread::UI);
+  target_runner->PostTask(
       FROM_HERE, base::Bind(&GetMimeTypeOnUI, base::RetainedRef(source), path,
                             job->weak_factory_.GetWeakPtr()));
 
-  target_message_loop->task_runner()->PostTask(
+  target_runner->PostTask(
       FROM_HERE, base::Bind(&URLDataManagerIOSBackend::CallStartRequest,
                             make_scoped_refptr(source), path, request_id));
   return true;
 }
 
 URLDataSourceIOSImpl* URLDataManagerIOSBackend::GetDataSourceFromURL(
     const GURL& url) {
   // The input usually looks like: chrome://source_name/extra_bits?foo
   // so do a lookup using the host of the URL.
   DataSourceMap::iterator i = data_sources_.find(url.host());
@@ skipping 37 matching lines @@
   // Forward this data on to the pending net::URLRequest, if it exists.
   PendingRequestMap::iterator i = pending_requests_.find(request_id);
   if (i != pending_requests_.end()) {
     URLRequestChromeJob* job(i->second);
     pending_requests_.erase(i);
     job->DataAvailable(bytes);
   }
 }
 
 }  // namespace web