Remove all remaining traces of MessageLoopProxy.

chrome/browser/printing/cloud_print/test/cloud_print_proxy_process_browsertest.cc

 // Copyright (c) 2012 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.
 
 // Create a service process that uses a Mock to respond to the browser in order
 // to test launching the browser using the cloud print policy check command
 // line switch.
 
 #include <stdint.h>
 
@@ skipping 301 matching lines @@
 class CloudPrintProxyPolicyStartupTest : public base::MultiProcessTest,
                                          public IPC::Listener {
  public:
   CloudPrintProxyPolicyStartupTest();
   ~CloudPrintProxyPolicyStartupTest() override;
 
   void SetUp() override;
   void TearDown() override;
 
   scoped_refptr<base::SingleThreadTaskRunner> IOTaskRunner() {
-    return BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO);
+    return BrowserThread::GetTaskRunnerForThread(BrowserThread::IO);
   }
   base::Process Launch(const std::string& name);
   void WaitForConnect();
   bool Send(IPC::Message* message);
   void ShutdownAndWaitForExitWithTimeout(base::Process process);
 
   // IPC::Listener implementation
   bool OnMessageReceived(const IPC::Message& message) override { return false; }
   void OnChannelConnected(int32_t peer_pid) override;
 
@@ skipping 187 matching lines @@
   // LocalState for the BrowserProcess.  Must be created before profiles are
   // constructed.
   chrome::TestingIOThreadState testing_io_thread_state;
 
   base::Process process =
       Launch("CloudPrintMockService_StartEnabledWaitForQuit");
   WaitForConnect();
   ShutdownAndWaitForExitWithTimeout(std::move(process));
   content::RunAllPendingInMessageLoop();
 }