Remove all remaining traces of MessageLoopProxy.

components/drive/file_system/get_file_for_saving_operation_unittest.cc

 // Copyright 2013 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 "components/drive/chromeos/file_system/get_file_for_saving_operation.h"
 
 #include <stdint.h>
 
 #include "base/callback.h"
 #include "base/files/file_path.h"
@@ skipping 46 matching lines @@
 class GetFileForSavingOperationTest : public OperationTestBase {
  protected:
   // FileWriteWatcher requires TYPE_IO message loop to run.
   GetFileForSavingOperationTest()
       : OperationTestBase(content::TestBrowserThreadBundle::IO_MAINLOOP) {
   }
 
   void SetUp() override {
     OperationTestBase::SetUp();
 
-    file_task_runner_ = content::BrowserThread::GetMessageLoopProxyForThread(
+    file_task_runner_ = content::BrowserThread::GetTaskRunnerForThread(
         content::BrowserThread::FILE);
 
     operation_.reset(new GetFileForSavingOperation(
         logger(), blocking_task_runner(), file_task_runner_.get(), &delegate_,
         scheduler(), metadata(), cache(), temp_dir()));
     operation_->file_write_watcher_for_testing()->DisableDelayForTesting();
   }
 
   TestDelegate delegate_;
   std::unique_ptr<GetFileForSavingOperation> operation_;
@@ skipping 73 matching lines @@
       google_apis::test_util::CreateCopyResultCallback(
           &error, &local_path, &entry));
   content::RunAllBlockingPoolTasksUntilIdle();
 
   // Checks that an error is returned.
   EXPECT_EQ(FILE_ERROR_EXISTS, error);
 }
 
 }  // namespace file_system
 }  // namespace drive