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

chrome/browser/extensions/extension_prefs_unittest.cc

 // 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.
 
 #include "extension_prefs_unittest.h"
 
 #include "base/basictypes.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/path_service.h"
 #include "base/prefs/mock_pref_change_callback.h"
 #include "base/prefs/public/pref_change_registrar.h"
 #include "base/stl_util.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_pref_value_map.h"
 #include "chrome/browser/extensions/extension_prefs.h"
-#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/pref_service_syncable.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/common/extensions/permissions/permission_set.h"
 #include "chrome/common/extensions/permissions/permissions_info.h"
+#include "components/user_prefs/pref_registry_syncable.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/test/mock_notification_observer.h"
 #include "sync/api/string_ordinal.h"
 
 using base::Time;
 using base::TimeDelta;
 using content::BrowserThread;
 
 namespace {
@@ skipping 1214 matching lines @@
 
  private:
   scoped_refptr<const Extension> extension_a_;
   scoped_refptr<const Extension> extension_b_;
   scoped_refptr<const Extension> extension_c_;
 };
 TEST_F(ExtensionPrefsBlacklistedExtensions,
        ExtensionPrefsBlacklistedExtensions) {}
 
 }  // namespace extensions