Automated IWYU fix for TaskRunner includes.

cc/resources/resource_pool_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 "cc/resources/resource_pool.h"
 
 #include <stddef.h>
 
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/resources/resource_util.h"
 #include "cc/resources/scoped_resource.h"
 #include "cc/test/fake_resource_provider.h"
 #include "cc/test/test_context_provider.h"
 #include "cc/test/test_shared_bitmap_manager.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace cc {
 
@@ skipping 424 matching lines @@
   // 100x100 is an exact match and should succeed. A subsequent request for
   // the same size should fail (the resource is already in use).
   Resource* resource =
       resource_pool_->ReuseResource(gfx::Size(100, 100), format, color_space);
   EXPECT_EQ(nullptr, resource_pool_->ReuseResource(gfx::Size(100, 100), format,
                                                    color_space));
   CheckAndReturnResource(resource);
 }
 
 }  // namespace cc