[iOS] Upstream preference names used by iOS

ios/chrome/browser/pref_names.h

 // Copyright 2014 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 IOS_CHROME_BROWSER_PREF_NAMES_H_
 #define IOS_CHROME_BROWSER_PREF_NAMES_H_
 
 namespace ios {
 namespace prefs {
 
 // Preferences in ios::prefs:: are temporary shared with desktop Chrome.
 // Non-shared preferences should be in the prefs:: namespace (no ios::).
 extern const char kAcceptLanguages[];
 
 }  // namespace prefs
 }  // namespace ios
 
 namespace prefs {
 
+extern const char kContextualSearchEnabled[];
 extern const char kIosBookmarkFolderDefault[];
 extern const char kIosBookmarkPromoAlreadySeen[];
+extern const char kIosHandoffToOtherDevices[];
+extern const char kMetricsReportingWifiOnly[];
+extern const char kNetworkPredictionWifiOnly[];
+extern const char kNtpShownBookmarksFolder[];
 extern const char kPaymentsPreferredUserId[];
 extern const char kShowMemoryDebuggingTools[];
 
+extern const char kVoiceSearchLocale[];
+extern const char kVoiceSearchTTS[];
+
+extern const char kSigninLastAccounts[];
+extern const char kSigninSharedAuthenticationUserId[];
+extern const char kSigninShouldPromptForSigninAgain[];
+
+extern const char kOmniboxGeolocationAuthorizationState[];
+extern const char kOmniboxGeolocationLastAuthorizationAlertVersion[];
+
+extern const char kDoodleAltText[];
+extern const char kDoodleExpirationTimeInSeconds[];
+extern const char kDoodleHref[];
+extern const char kDoodleLastRequestTimeInSeconds[];
+extern const char kDoodleQuery[];
+
 }  // namespace prefs
 
 #endif  // IOS_CHROME_BROWSER_PREF_NAMES_H_