[Sync] Disable search engines datatype by default.

chrome/common/chrome_switches.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.
 
 // Defines all the command-line switches used by Chrome.
 
 #ifndef CHROME_COMMON_CHROME_SWITCHES_H_
 #define CHROME_COMMON_CHROME_SWITCHES_H_
 #pragma once
 
@@ skipping 99 matching lines @@
 extern const char kDisableSyncAppSettings[];
 extern const char kDisableSyncApps[];
 extern const char kDisableSyncAppNotifications[];
 extern const char kDisableSyncAutofill[];
 extern const char kDisableSyncAutofillProfile[];
 extern const char kDisableSyncBookmarks[];
 extern const char kDisableSyncExtensionSettings[];
 extern const char kDisableSyncExtensions[];
 extern const char kDisableSyncPasswords[];
 extern const char kDisableSyncPreferences[];
-extern const char kDisableSyncSearchEngines[];
+extern const char kEnableSyncSearchEngines[];
 extern const char kDisableSyncThemes[];
 extern const char kDisableSyncTypedUrls[];
 extern const char kDisableTLS1[];
 extern const char kDisableTranslate[];
 extern const char kDisableWebResources[];
 extern const char kDisableZeroBrowsersOpenForTests[];
 extern const char kDiskCacheDir[];
 extern const char kDiskCacheSize[];
 extern const char kDnsLogDetails[];
 extern const char kDnsPrefetchDisable[];
@@ skipping 286 matching lines @@
 #else
 extern const char kEnablePrintPreview[];
 #endif
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace switches
 
 #endif  // CHROME_COMMON_CHROME_SWITCHES_H_