Automated IWYU fix for TaskRunner includes.

cc/test/fake_layer_tree_host.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 "cc/test/fake_layer_tree_host.h"
 
 #include "base/memory/ptr_util.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/animation/animation_host.h"
 #include "cc/layers/layer.h"
 #include "cc/test/test_task_graph_runner.h"
 #include "cc/trees/mutator_host.h"
 
 namespace cc {
 
 FakeLayerTreeHost::FakeLayerTreeHost(FakeLayerTreeHostClient* client,
                                      LayerTreeHost::InitParams* params,
@@ skipping 77 matching lines @@
   TreeSynchronizer::PushLayerProperties(root_layer()->layer_tree_host(),
                                         pending_tree());
   mutator_host()->PushPropertiesTo(host_impl_.mutator_host());
 
   pending_tree()->property_trees()->scroll_tree.PushScrollUpdatesFromMainThread(
       property_trees(), pending_tree());
   return pending_tree()->root_layer_for_testing();
 }
 
 }  // namespace cc