Add the AsyncPolicyProvider and AsyncPolicyLoader

chrome/browser/policy/async_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_ASYNC_POLICY_PROVIDER_H_
+#define CHROME_BROWSER_POLICY_ASYNC_POLICY_PROVIDER_H_
+#pragma once
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/policy/configuration_policy_provider.h"
+
+namespace policy {
+
+class AsyncPolicyLoader;
+class PolicyBundle;
+
+// A policy provider that loads its policies asynchronously in the FILE thread.

[Mattias Nissler (ping if slow), 2012/06/04 08:48:26]

in or on? on is more familiar to me.

[Joao da Silva, 2012/06/04 14:05:06]

Done.

+// Platform-specific providers are created by passing an implementation of
+// AsyncPolicyLoader to a new AsyncPolicyProvider.
+class AsyncPolicyProvider : public ConfigurationPolicyProvider {
+ public:
+  // Takes ownership of |loader|.
+  AsyncPolicyProvider(const PolicyDefinitionList* policy_list,
+                      AsyncPolicyLoader* loader);

[Mattias Nissler (ping if slow), 2012/06/04 08:48:26]

should declare a scoped_ptr<AsyncPolicyLoader> argument then.

[Joao da Silva, 2012/06/04 14:05:06]

Done.

+  virtual ~AsyncPolicyProvider();
+
+  // ConfigurationPolicyProvider implementation.
+  virtual void RefreshPolicies() OVERRIDE;
+
+ private:
+  // Resumes initialization once the loops are spinning.
+  void InitWithLoopsReady();
+
+  // Helper for RefreshPolicies().
+  void PostRefreshingReload();
+
+  // Invoked with the latest bundle loaded by the |loader_|.
+  void OnLoaderReloaded(scoped_ptr<PolicyBundle> bundle);
+
+  // The |loader_| that does the platform-specific policy loading. It lives
+  // in the FILE thread, and always outlives |this|.
+  AsyncPolicyLoader* loader_;
+
+  // Used to get WeakPtrs() to |this| on UI. These are used for the update
+  // callback passed to |loader_| and for the RefreshPolicies() tasks.
+  base::WeakPtrFactory<AsyncPolicyProvider> weak_factory_;
+
+  // Number of RefreshPolicies() calls that have been received before
+  // OnLoaderReloaded() has been invoked. Updates are only triggered after the
+  // last RefreshPolicies() request has triggered its reload, to make sure
+  // its observer will see the policy changes made before calling
+  // RefreshPolicies().
+  int pending_refreshes_;
+
+  DISALLOW_COPY_AND_ASSIGN(AsyncPolicyProvider);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_ASYNC_POLICY_PROVIDER_H_