Add the partial screen magnifier to Chrome OS.

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 248 matching lines @@
 extern const char kLanguageMozcSuggestionsSize[];
 extern const char kLanguageRemapCapsLockKeyTo[];
 extern const char kLanguageRemapSearchKeyTo[];
 extern const char kLanguageRemapControlKeyTo[];
 extern const char kLanguageRemapAltKeyTo[];
 extern const char kLanguageXkbAutoRepeatEnabled[];
 extern const char kLanguageXkbAutoRepeatDelay[];
 extern const char kLanguageXkbAutoRepeatInterval[];
 extern const char kSpokenFeedbackEnabled[];
 extern const char kHighContrastEnabled[];
-extern const char kScreenMagnifierEnabled[];
 extern const char kScreenMagnifierScale[];
+extern const char kScreenMagnifierType[];
 extern const char kVirtualKeyboardEnabled[];
 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[];
@@ skipping 505 matching lines @@
 extern const char kInManagedMode[];
 
 extern const char kNetworkProfileWarningsLeft[];
 extern const char kNetworkProfileLastWarningTime[];
 
 extern const char kLastPolicyStatisticsUpdate[];
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_