Add missing IWYU message_loop.h includes.

third_party/WebKit/Source/platform/scheduler/base/task_queue_manager_perftest.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 "platform/scheduler/base/task_queue_manager.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/default_tick_clock.h"
 #include "platform/scheduler/base/task_queue_impl.h"
 #include "platform/scheduler/base/task_queue_manager_delegate_for_test.h"
 #include "platform/scheduler/base/task_queue_selector.h"
 #include "platform/scheduler/base/test_task_time_observer.h"
 #include "platform/scheduler/base/virtual_time_domain.h"
@@ skipping 193 matching lines @@
   Benchmark("run 10000 delayed tasks with eight queues",
             base::Bind(&TaskQueueManagerPerfTest::ResetAndCallTestDelayedTask,
                        base::Unretained(this), 10000));
 }
 
 // TODO(alexclarke): Add additional tests with different mixes of non-delayed vs
 // delayed tasks.
 
 }  // namespace scheduler
 }  // namespace blink