Remove calls to deprecated MessageLoop methods in ios.

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"
 #include "base/compiler_specific.h"
 #include "base/debug/alias.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "ios/web/public/browser_state.h"
 #include "ios/web/public/web_client.h"
 #include "ios/web/public/web_thread.h"
 #include "ios/web/webui/shared_resources_data_source_ios.h"
 #include "ios/web/webui/url_data_source_ios_impl.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
@@ skipping 424 matching lines @@
   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->PostTask(
+  target_message_loop->task_runner()->PostTask(
       FROM_HERE, base::Bind(&GetMimeTypeOnUI, base::RetainedRef(source), path,
                             job->weak_factory_.GetWeakPtr()));
 
-  target_message_loop->PostTask(
+  target_message_loop->task_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