Move policy code into components/policy.

chrome/browser/policy/policy_service.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 "chrome/browser/policy/policy_service.h"
-
-#include "base/values.h"
-
-namespace policy {
-
-PolicyChangeRegistrar::PolicyChangeRegistrar(PolicyService* policy_service,
-                                             const PolicyNamespace& ns)
-    : policy_service_(policy_service),
-      ns_(ns) {}
-
-PolicyChangeRegistrar::~PolicyChangeRegistrar() {
-  if (!callback_map_.empty())
-    policy_service_->RemoveObserver(ns_.domain, this);
-}
-
-void PolicyChangeRegistrar::Observe(const std::string& policy_name,
-                                    const UpdateCallback& callback) {
-  if (callback_map_.empty())
-    policy_service_->AddObserver(ns_.domain, this);
-  callback_map_[policy_name] = callback;
-}
-
-void PolicyChangeRegistrar::OnPolicyUpdated(const PolicyNamespace& ns,
-                                            const PolicyMap& previous,
-                                            const PolicyMap& current) {
-  if (ns != ns_)
-    return;
-  for (CallbackMap::iterator it = callback_map_.begin();
-       it != callback_map_.end(); ++it) {
-    const Value* prev = previous.GetValue(it->first);
-    const Value* cur = current.GetValue(it->first);
-    if (!base::Value::Equals(prev, cur))
-      it->second.Run(prev, cur);
-  }
-}
-
-}  // namespace policy