Add UMA for policy load result of enrolled Chrome OS devices.

chrome/browser/chromeos/policy/device_cloud_policy_store_chromeos.h

 // Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_CLOUD_POLICY_STORE_CHROMEOS_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_CLOUD_POLICY_STORE_CHROMEOS_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
@@ skipping 58 matching lines @@
   void OnPolicyStored();
 
   // Re-syncs policy and status from |device_settings_service_|.
   void UpdateFromService();
 
   chromeos::DeviceSettingsService* device_settings_service_;
   EnterpriseInstallAttributes* install_attributes_;
 
   scoped_refptr<base::SequencedTaskRunner> background_task_runner_;
 
+  // Ensure that UMA stats are only reported once per browser start.
+  bool uma_done_;
+
   base::WeakPtrFactory<DeviceCloudPolicyStoreChromeOS> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceCloudPolicyStoreChromeOS);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_CLOUD_POLICY_STORE_CHROMEOS_H_