Introduce ThreadTaskRunnerHandle::OverrideForTesting and TestMockTimeTaskRunner::ScopedContext.

chrome/browser/chromeos/policy/browser_policy_connector_chromeos.cc

 // 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.
 
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 105 matching lines @@
           ->StartAuthPolicyService();
 
       device_active_directory_policy_manager_ =
           ActiveDirectoryPolicyManager::CreateForDevicePolicy(
               std::move(device_cloud_policy_store))
               .release();
       AddPolicyProvider(base::WrapUnique<ConfigurationPolicyProvider>(
           device_active_directory_policy_manager_));
     } else {
       state_keys_broker_ = base::MakeUnique<ServerBackedStateKeysBroker>(
-          chromeos::DBusThreadManager::Get()->GetSessionManagerClient(),
-          base::ThreadTaskRunnerHandle::Get());
+          chromeos::DBusThreadManager::Get()->GetSessionManagerClient());
 
       device_cloud_policy_manager_ = new DeviceCloudPolicyManagerChromeOS(
           std::move(device_cloud_policy_store),
           base::ThreadTaskRunnerHandle::Get(), state_keys_broker_.get());
       AddPolicyProvider(base::WrapUnique<ConfigurationPolicyProvider>(
           device_cloud_policy_manager_));
     }
   }
 
   global_user_cloud_policy_provider_ = new ProxyPolicyProvider();
@@ skipping 238 matching lines @@
         device_cloud_policy_manager_->device_store()->policy();
     if (policy_data) {
       affiliation_ids.insert(policy_data->device_affiliation_ids().begin(),
                              policy_data->device_affiliation_ids().end());
     }
   }
   return affiliation_ids;
 }
 
 }  // namespace policy