Introduce //components/user_prefs, use to eliminate c/b/prefs dependency in Autofill.

chrome/browser/chromeos/language_preferences.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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LANGUAGE_PREFERENCES_H_
 #define CHROME_BROWSER_CHROMEOS_LANGUAGE_PREFERENCES_H_
 
 #include <stddef.h>  // For size_t
 
-#include "chrome/browser/prefs/pref_registry_syncable.h"
+#include "components/user_prefs/pref_registry_syncable.h"
 
 class PrefRegistrySimple;
 
 // TODO(yusukes): Rename this file to input_method_preference.cc. Since
 // "language" usually means UI language, the current file name is confusing.
 // The namespace should also be changed to "namespace input_method {".
 
 // This file defines types and declare variables used in "Languages and
 // Input" settings in Chromium OS.
 namespace chromeos {
@@ skipping 141 matching lines @@
 // the login screen.
 extern const char kPreferredKeyboardLayout[];
 
 // Registers non-user prefs for the default keyboard layout on the login screen.
 void RegisterPrefs(PrefRegistrySimple* registry);
 
 }  // language_prefs
 }  // chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LANGUAGE_PREFERENCES_H_