Add policy for limiting the session length

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 268 matching lines @@
 extern const char kChromeOSReleaseNotesVersion[];
 extern const char kUseSharedProxies[];
 extern const char kOAuth1Token[];
 extern const char kOAuth1Secret[];
 extern const char kEnableCrosDRM[];
 extern const char kDisplayOverscans[];
 extern const char kPrimaryDisplayID[];
 extern const char kSecondaryDisplayLayout[];
 extern const char kSecondaryDisplayOffset[];
 extern const char kSecondaryDisplays[];
+extern const char kSessionStartTime[];
+extern const char kSessionLengthLimit[];
 #endif  // defined(OS_CHROMEOS)
 extern const char kIpcDisabledMessages[];
 extern const char kShowHomeButton[];
 extern const char kRecentlySelectedEncoding[];
 extern const char kDeleteBrowsingHistory[];
 extern const char kDeleteDownloadHistory[];
 extern const char kDeleteCache[];
 extern const char kDeleteCookies[];
 extern const char kDeletePasswords[];
 extern const char kDeleteFormData[];
@@ skipping 504 matching lines @@
 
 extern const char kLastPolicyStatisticsUpdate[];
 
 #if defined(OS_CHROMEOS)
 extern const char kRLZBrand[];
 #endif
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_