Remove all remaining traces of MessageLoopProxy.

headless/lib/browser/headless_browser_impl.cc

 // Copyright 2015 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 "headless/lib/browser/headless_browser_impl.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
@@ skipping 69 matching lines @@
     const GURL& initial_url,
     const gfx::Size& size) {
   return CreateWebContentsBuilder()
       .SetInitialURL(initial_url)
       .SetWindowSize(size)
       .Build();
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 HeadlessBrowserImpl::BrowserMainThread() const {
-  return content::BrowserThread::GetMessageLoopProxyForThread(
+  return content::BrowserThread::GetTaskRunnerForThread(
       content::BrowserThread::UI);
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 HeadlessBrowserImpl::BrowserFileThread() const {
-  return content::BrowserThread::GetMessageLoopProxyForThread(
+  return content::BrowserThread::GetTaskRunnerForThread(
       content::BrowserThread::FILE);
 }
 
 void HeadlessBrowserImpl::Shutdown() {
   DCHECK(BrowserMainThread()->BelongsToCurrentThread());
   BrowserMainThread()->PostTask(FROM_HERE,
                                 base::MessageLoop::QuitWhenIdleClosure());
 }
 
 std::vector<HeadlessWebContents*> HeadlessBrowserImpl::GetAllWebContents() {
@@ skipping 86 matching lines @@
 
   // Child processes should not end up here.
   base::CommandLine command_line(options.argc, options.argv);
   DCHECK(!command_line.HasSwitch(switches::kProcessType));
 #endif
   return RunContentMain(std::move(options),
                         std::move(on_browser_start_callback));
 }
 
 }  // namespace headless