Get rid of the ability to unregister preferences.

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 266 matching lines @@
 extern const char kScreenMagnifierScale[];
 extern const char kVirtualKeyboardEnabled[];
 extern const char kShouldAlwaysShowAccessibilityMenu[];
 extern const char kLabsAdvancedFilesystemEnabled[];
 extern const char kLabsMediaplayerEnabled[];
 extern const char kEnableScreenLock[];
 extern const char kShowPlanNotifications[];
 extern const char kShow3gPromoNotification[];
 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[];
 extern const char kPowerAcScreenDimDelayMs[];
 extern const char kPowerAcScreenOffDelayMs[];
@@ skipping 559 matching lines @@
 extern const char kRLZDisabled[];
 #endif
 
 #if defined(ENABLE_APP_LIST)
 extern const char kAppListProfile[];
 #endif
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_