Move prefs::kLastPolicyStatisticsUpdate to the policy component.

chrome/common/pref_names.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.
 
 // Constants for the names of various preferences, for easier changing.
 
 #ifndef CHROME_COMMON_PREF_NAMES_H_
 #define CHROME_COMMON_PREF_NAMES_H_
 
 #include <stddef.h>
@@ skipping 869 matching lines @@
 extern const char kOverscrollMinimumThresholdStartTouchpad[];
 extern const char kOverscrollVerticalThresholdStart[];
 extern const char kOverscrollHorizontalResistThreshold[];
 extern const char kOverscrollVerticalResistThreshold[];
 extern const char kGestureConfigIsTrustworthy[];
 #endif
 
 extern const char kNetworkProfileWarningsLeft[];
 extern const char kNetworkProfileLastWarningTime[];
 
-extern const char kLastPolicyStatisticsUpdate[];
-
 #if defined(OS_CHROMEOS)
 extern const char kRLZBrand[];
 extern const char kRLZDisabled[];
 #endif
 
 extern const char kAppListProfile[];
 extern const char kRestartWithAppList[];
 
 extern const char kLastAppListLaunchPing[];
 extern const char kAppListLaunchCount[];
 extern const char kLastAppListAppLaunchPing[];
 extern const char kAppListAppLaunchCount[];
 
 extern const char kModuleConflictBubbleShown[];
 
 extern const char kDRMSalt[];
 extern const char kEnableDRM[];
 
 extern const char kWatchdogExtensionActive[];
 
 extern const char kProfilePreferenceHashes[];
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_