[Extensions] Remove unused parts of the preferencesPrivate API

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 544 matching lines @@
 extern const char kCrossDevicePromoNumDevices[];
 extern const char kCrossDevicePromoLastDeviceActiveTime[];
 #endif
 
 extern const char kWebAppCreateOnDesktop[];
 extern const char kWebAppCreateInAppsMenu[];
 extern const char kWebAppCreateInQuickLaunchBar[];
 
 extern const char kGeolocationAccessToken[];
 
-#if BUILDFLAG(ENABLE_GOOGLE_NOW)
-extern const char kGoogleGeolocationAccessEnabled[];
-#endif
 extern const char kGoogleNowLauncherEnabled[];
 
 extern const char kDefaultAudioCaptureDevice[];
 extern const char kDefaultVideoCaptureDevice[];
 extern const char kMediaDeviceIdSalt[];
 
 extern const char kPrintPreviewStickySettings[];
 extern const char kCloudPrintRoot[];
 extern const char kCloudPrintProxyEnabled[];
 extern const char kCloudPrintProxyId[];
@@ skipping 223 matching lines @@
 #if defined(GOOGLE_CHROME_BUILD)
 extern const char kMediaRouterCloudServicesPrefSet[];
 extern const char kMediaRouterEnableCloudServices[];
 #endif  // defined(GOOGLE_CHROME_BUILD)
 extern const char kMediaRouterFirstRunFlowAcknowledged[];
 #endif
 
 }  // namespace prefs
 
 #endif  // CHROME_COMMON_PREF_NAMES_H_