Automated IWYU fix for TaskRunner includes.

third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl_unittest.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/child/worker_scheduler_impl.h"
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "cc/test/ordered_simple_task_runner.h"
 #include "platform/scheduler/base/test_time_source.h"
 #include "platform/scheduler/child/scheduler_tqm_delegate_for_test.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using testing::ElementsAreArray;
 
@@ skipping 373 matching lines @@
                                      "Post RecordTimelineTask",
                                      "RunUntilIdle begin @ 385",
                                      "run RecordTimelineTask @ 385",
                                      "RunUntilIdle end @ 385"};
 
   EXPECT_THAT(timeline, ElementsAreArray(expected_timeline));
 }
 
 }  // namespace scheduler
 }  // namespace blink