Update server-backed state key generation.

chromeos/system/statistics_provider.h

 // 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.
 
 #ifndef CHROMEOS_SYSTEM_STATISTICS_PROVIDER_H_
 #define CHROMEOS_SYSTEM_STATISTICS_PROVIDER_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 31 matching lines @@
 
 // Offer coupon code key.
 CHROMEOS_EXPORT extern const char kOffersCouponCodeKey[];
 
 // Offer group key.
 CHROMEOS_EXPORT extern const char kOffersGroupCodeKey[];
 
 // Release Brand Code key.
 CHROMEOS_EXPORT extern const char kRlzBrandCodeKey[];
 
+// The serial number of the disk the root device is on.
+CHROMEOS_EXPORT extern const char kDiskSerialNumber[];
+
 // This interface provides access to Chrome OS statistics.
 class CHROMEOS_EXPORT StatisticsProvider {
  public:
   // Starts loading the machine statistics. File operations are performed on
   // |file_task_runner|.
   virtual void StartLoadingMachineStatistics(
       const scoped_refptr<base::TaskRunner>& file_task_runner,
       bool load_oem_manifest) = 0;
 
   // Retrieves the named machine statistic (e.g. "hardware_class"). If |name|
@@ skipping 17 matching lines @@
   static void SetTestProvider(StatisticsProvider* test_provider);
 
  protected:
   virtual ~StatisticsProvider() {}
 };
 
 }  // namespace system
 }  // namespace chromeos
 
 #endif  // CHROMEOS_SYSTEM_STATISTICS_PROVIDER_H_