Rewrite base::Bind into base::BindOnce on trivial cases in base

base/test/scoped_task_scheduler.cc

 // Copyright 2016 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 "base/test/scoped_task_scheduler.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 218 matching lines @@
   // TestTaskScheduler doesn't create threads so this does nothing.
 }
 
 bool TestTaskScheduler::PostTask(std::unique_ptr<internal::Task> task,
                                  const SequenceToken& sequence_token) {
   DCHECK(task);
   if (!task_tracker_.WillPostTask(task.get()))
     return false;
   internal::Task* const task_ptr = task.get();
   return MessageLoopTaskRunner()->PostDelayedTask(
-      task_ptr->posted_from, Bind(&TestTaskScheduler::RunTask, Unretained(this),
-                                  Passed(&task), sequence_token),
+      task_ptr->posted_from,
+      BindOnce(&TestTaskScheduler::RunTask, Unretained(this), Passed(&task),
+               sequence_token),
       task_ptr->delay);
 }
 
 void TestTaskScheduler::RunTask(std::unique_ptr<internal::Task> task,
                                 const SequenceToken& sequence_token) {
   DCHECK(!saved_task_runner_);
   saved_task_runner_ = MessageLoop::current()->task_runner();
 
   // Clear the MessageLoop TaskRunner to allow TaskTracker to register its own
   // Thread/SequencedTaskRunnerHandle as appropriate.
@@ skipping 71 matching lines @@
   DCHECK_EQ(task_scheduler_, TaskScheduler::GetInstance());
 
   // Per contract, call JoinForTesting() before deleting the TaskScheduler.
   TaskScheduler::GetInstance()->JoinForTesting();
 
   TaskScheduler::SetInstance(nullptr);
 }
 
 }  // namespace test
 }  // namespace base