Revert of ios: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

ios/web/shell/shell_url_request_context_getter.cc

 // 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/shell/shell_url_request_context_getter.h"
 
 #include "base/base_paths.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/path_service.h"
@@ skipping 22 matching lines @@
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_storage.h"
 #include "net/url_request/url_request_job_factory_impl.h"
 
 namespace web {
 
 ShellURLRequestContextGetter::ShellURLRequestContextGetter(
     const base::FilePath& base_path,
     const scoped_refptr<base::SingleThreadTaskRunner>& network_task_runner,
     const scoped_refptr<base::SingleThreadTaskRunner>& file_task_runner,
-    const scoped_refptr<base::SingleThreadTaskRunner>& cache_task_runner)
+    const scoped_refptr<base::MessageLoopProxy>& cache_task_runner)
     : base_path_(base_path),
       file_task_runner_(file_task_runner),
       network_task_runner_(network_task_runner),
       cache_task_runner_(cache_task_runner),
       proxy_config_service_(new net::ProxyConfigServiceIOS),
       net_log_(new net::NetLog()) {
 }
 
 ShellURLRequestContextGetter::~ShellURLRequestContextGetter() {
 }
@@ skipping 96 matching lines @@
 
   return url_request_context_.get();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 ShellURLRequestContextGetter::GetNetworkTaskRunner() const {
   return network_task_runner_;
 }
 
 }  // namespace web