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

chrome/browser/prefs/proxy_policy_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 "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/policy/mock_configuration_policy_provider.h"
 #include "chrome/browser/policy/policy_map.h"
 #include "chrome/browser/policy/policy_service_impl.h"
 #include "chrome/browser/prefs/browser_prefs.h"
-#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/pref_service_mock_builder.h"
 #include "chrome/browser/prefs/pref_service_syncable.h"
 #include "chrome/browser/prefs/proxy_config_dictionary.h"
 #include "chrome/browser/prefs/proxy_prefs.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
+#include "components/user_prefs/pref_registry_syncable.h"
 #include "policy/policy_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::testing::Return;
 using ::testing::_;
 
 namespace policy {
 
 namespace {
 
@@ skipping 184 matching lines @@
 
   // Try a second time time with the managed PrefStore in place, the
   // auto-detect should be overridden. The default pref store must be
   // in place with the appropriate default value for this to work.
   prefs.reset(CreatePrefService(true));
   ProxyConfigDictionary dict2(prefs->GetDictionary(prefs::kProxy));
   assertProxyModeWithoutParams(dict2, ProxyPrefs::MODE_DIRECT);
 }
 
 }  // namespace policy