Automated IWYU fix for TaskRunner includes.

components/metrics/metrics_state_manager.h

 // Copyright 2014 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.
 
 #ifndef COMPONENTS_METRICS_METRICS_STATE_MANAGER_H_
 #define COMPONENTS_METRICS_METRICS_STATE_MANAGER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/metrics/field_trial.h"
+#include "base/single_thread_task_runner.h"
 #include "components/metrics/client_info.h"
 
 class PrefService;
 class PrefRegistrySimple;
 
 namespace metrics {
 
 class ClonedInstallDetector;
 class EnabledStateProvider;
 
@@ skipping 149 matching lines @@
   EntropySourceType entropy_source_returned_;
 
   std::unique_ptr<ClonedInstallDetector> cloned_install_detector_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsStateManager);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_METRICS_STATE_MANAGER_H_