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

chrome/browser/translate/translate_prefs.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/translate/translate_prefs.h"
 
 #include "base/prefs/pref_service.h"
 #include "base/string_util.h"
-#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
+#include "components/user_prefs/pref_registry_syncable.h"
 
 const char TranslatePrefs::kPrefTranslateLanguageBlacklist[] =
     "translate_language_blacklist";
 const char TranslatePrefs::kPrefTranslateSiteBlacklist[] =
     "translate_site_blacklist";
 const char TranslatePrefs::kPrefTranslateWhitelists[] =
     "translate_whitelists";
 const char TranslatePrefs::kPrefTranslateDeniedCount[] =
     "translate_denied_count";
 const char TranslatePrefs::kPrefTranslateAcceptedCount[] =
@@ skipping 247 matching lines @@
     DCHECK(!target_language->empty());
     return !target_language->empty();
   }
   return false;
 }
 
 bool TranslatePrefs::IsListEmpty(const char* pref_id) const {
   const ListValue* blacklist = prefs_->GetList(pref_id);
   return (blacklist == NULL || blacklist->empty());
 }