Move user cloud policy to BrowserProcess.

chrome/browser/policy/cloud_policy_provider.h

+// Copyright (c) 2011 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_CLOUD_POLICY_PROVIDER_H_
+#define CHROME_BROWSER_POLICY_CLOUD_POLICY_PROVIDER_H_
+#pragma once
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "base/observer_list.h"
+#include "chrome/browser/policy/cloud_policy_cache_base.h"
+#include "chrome/browser/policy/configuration_policy_provider.h"
+#include "chrome/browser/policy/policy_map.h"
+
+namespace policy {
+
+// A policy provider having multiple backend caches, combining their relevant
+// PolicyMaps and keeping the result cached. The underlying caches are kept as
+// weak references and can be added  dynamically. Also the
+// |CloudPolicyProvider| instance listens to cache-notifications and removes
+// the caches automatically when they go away. The order in which the caches are
+// stored matters! The first cache is applied as is and the following caches
+// only contribute the not-yet applied policies. There are two functions to add
+// a new cache:
+//   PrependCache(cache): adds |cache| to the front (i.e. most important cache).
+//   AppendCache(cache):  adds |cache| to the back (i.e. least important cache).
+class CloudPolicyProvider : public ConfigurationPolicyProvider,
+                            public CloudPolicyCacheBase::Observer {
+ public:
+  CloudPolicyProvider(const PolicyDefinitionList* policy_list,
+                      CloudPolicyCacheBase::PolicyLevel level);
+  virtual ~CloudPolicyProvider();
+
+  // ConfigurationPolicyProvider implementation.
+  virtual bool Provide(ConfigurationPolicyStoreInterface* store) OVERRIDE;
+  virtual bool IsInitializationComplete() const OVERRIDE;
+  virtual void AddObserver(ConfigurationPolicyProvider::Observer* observer)
+      OVERRIDE;
+  virtual void RemoveObserver(ConfigurationPolicyProvider::Observer* observer)
+      OVERRIDE;
+
+  // CloudPolicyCacheBase::Observer implementation.
+  virtual void OnCacheUpdate(CloudPolicyCacheBase* cache) OVERRIDE;
+  virtual void OnCacheGoingAway(CloudPolicyCacheBase* cache) OVERRIDE;
+
+  // Adds a new instance of CloudPolicyCacheBase to the end of |caches_|.
+  // Does not take ownership of |cache| and listens to OnCacheGoingAway to
+  // automatically remove it from |caches_|.
+  void AppendCache(CloudPolicyCacheBase* cache);
+
+  // Adds a new instance of CloudPolicyCacheBase to the beginning of |caches_|.
+  // Does not take ownership of |cache| and listens to OnCacheGoingAway to
+  // automatically remove it from |caches_|.
+  void PrependCache(CloudPolicyCacheBase* cache);
+
+ private:
+  friend class CloudPolicyProviderTest;
+
+  // Detecting proxy-policies since they need a special handling when combining
+  // policy maps.
+  static ConfigurationPolicyType proxy_policies[];
+  static bool is_proxy_policy(ConfigurationPolicyType policy);
+  static unsigned int proxy_policy_count();
+  // Combines two PolicyMap and stores the result in out_map. The policies in
+  // |base| take precedence over the policies in |overlay|. Proxy policies are
+  // only applied in groups, that is if at least one proxy policy is present in
+  // |base| then no proxy related policy of |overlay| will be applied.
+  void CombineTwoPolicyMaps(const PolicyMap& base,
+                            const PolicyMap& overlay,
+                            PolicyMap* out_map);
+
+  // Recompute |combined_| from |caches_| and trigger an OnUpdatePolicy if
+  // something changed. This is called whenever a change in one of the caches
+  // is observed. For i=0..n-1: |caches_[i]| will contribute all its policies
+  // except those already provided by |caches_[0]|..|caches_[i-1]|. Proxy
+  // related policies are handled as a special case: they are only applied in
+  // groups.
+  void RecombineCachesAndMaybeTriggerUpdate();
+
+  // The underlying policy caches.
+  typedef std::vector<CloudPolicyCacheBase*> ListType;
+  ListType caches_;
+
+  // Policy level this provider will handle.
+  CloudPolicyCacheBase::PolicyLevel level_;
+
+  // Provider observers that are registered with this provider.
+  ObserverList<ConfigurationPolicyProvider::Observer, true> observer_list_;
+
+  // The currently valid combination of all the maps in |caches_|. Will be
+  // applied as is on call of Provide.
+  PolicyMap combined_;
+
+  DISALLOW_COPY_AND_ASSIGN(CloudPolicyProvider);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_POLICY_CLOUD_POLICY_PROVIDER_H_