Enable user policy handling through the new cloud policy stack.

chrome/browser/policy/proxy_policy_provider.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_POLICY_PROXY_POLICY_PROVIDER_H_
+#define CHROME_BROWSER_POLICY_PROXY_POLICY_PROVIDER_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/policy/configuration_policy_provider.h"
+
+namespace policy {
+
+// A policy provider implementation that acts as a proxy for another policy
+// provider, swappable at any point.
+class ProxyPolicyProvider : public ConfigurationPolicyProvider,
+                            public ConfigurationPolicyProvider::Observer {
+ public:
+  ProxyPolicyProvider();
+  virtual ~ProxyPolicyProvider();
+
+  // Updates the provider this proxy delegates to.
+  void SetDelegate(ConfigurationPolicyProvider* delegate);
+
+  // ConfigurationPolicyProvider:
+  virtual void RefreshPolicies() OVERRIDE;
+
+  // ConfigurationPolicyProvider::Observer:
+  virtual void OnUpdatePolicy(ConfigurationPolicyProvider* provider) OVERRIDE;
+  virtual void OnProviderGoingAway(
+      ConfigurationPolicyProvider* provider) OVERRIDE;
+
+ private:
+  scoped_ptr<ConfigurationPolicyObserverRegistrar> registrar_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProxyPolicyProvider);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_PROXY_POLICY_PROVIDER_H_