Move policy code into components/policy.

chrome/browser/policy/policy_service.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_POLICY_SERVICE_H_
-#define CHROME_BROWSER_POLICY_POLICY_SERVICE_H_
-
-#include <map>
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "components/policy/core/common/policy_map.h"
-#include "components/policy/core/common/policy_namespace.h"
-
-namespace policy {
-
-// The PolicyService merges policies from all available sources, taking into
-// account their priorities. Policy clients can retrieve policy for their domain
-// and register for notifications on policy updates.
-//
-// The PolicyService is available from BrowserProcess as a global singleton.
-// There is also a PolicyService for browser-wide policies available from
-// BrowserProcess as a global singleton.
-class PolicyService {
- public:
-  class Observer {
-   public:
-    // Invoked whenever policies for the given |ns| namespace are modified.
-    // This is only invoked for changes that happen after AddObserver is called.
-    // |previous| contains the values of the policies before the update,
-    // and |current| contains the current values.
-    virtual void OnPolicyUpdated(const PolicyNamespace& ns,
-                                 const PolicyMap& previous,
-                                 const PolicyMap& current) = 0;
-
-    // Invoked at most once for each |domain|, when the PolicyService becomes
-    // ready. If IsInitializationComplete() is false, then this will be invoked
-    // once all the policy providers have finished loading their policies for
-    // |domain|.
-    virtual void OnPolicyServiceInitialized(PolicyDomain domain) {}
-
-   protected:
-    virtual ~Observer() {}
-  };
-
-  virtual ~PolicyService() {}
-
-  // Observes changes to all components of the given |domain|.
-  virtual void AddObserver(PolicyDomain domain, Observer* observer) = 0;
-
-  virtual void RemoveObserver(PolicyDomain domain, Observer* observer) = 0;
-
-  virtual const PolicyMap& GetPolicies(const PolicyNamespace& ns) const = 0;
-
-  // The PolicyService loads policy from several sources, and some require
-  // asynchronous loads. IsInitializationComplete() returns true once all
-  // sources have loaded their policies for the given |domain|.
-  // It is safe to read policy from the PolicyService even if
-  // IsInitializationComplete() is false; there will be an OnPolicyUpdated()
-  // notification once new policies become available.
-  //
-  // OnPolicyServiceInitialized() is called when IsInitializationComplete()
-  // becomes true, which happens at most once for each domain.
-  // If IsInitializationComplete() is already true for |domain| when an Observer
-  // is registered, then that Observer will not receive an
-  // OnPolicyServiceInitialized() notification.
-  virtual bool IsInitializationComplete(PolicyDomain domain) const = 0;
-
-  // Asks the PolicyService to reload policy from all available policy sources.
-  // |callback| is invoked once every source has reloaded its policies, and
-  // GetPolicies() is guaranteed to return the updated values at that point.
-  virtual void RefreshPolicies(const base::Closure& callback) = 0;
-};
-
-// A registrar that only observes changes to particular policies within the
-// PolicyMap for the given policy namespace.
-class PolicyChangeRegistrar : public PolicyService::Observer {
- public:
-  typedef base::Callback<void(const Value*, const Value*)> UpdateCallback;
-
-  // Observes updates to the given (domain, component_id) namespace in the given
-  // |policy_service|, and notifies |observer| whenever any of the registered
-  // policy keys changes. Both the |policy_service| and the |observer| must
-  // outlive |this|.
-  PolicyChangeRegistrar(PolicyService* policy_service,
-                        const PolicyNamespace& ns);
-
-  virtual ~PolicyChangeRegistrar();
-
-  // Will invoke |callback| whenever |policy_name| changes its value, as long
-  // as this registrar exists.
-  // Only one callback can be registed per policy name; a second call with the
-  // same |policy_name| will overwrite the previous callback.
-  void Observe(const std::string& policy_name, const UpdateCallback& callback);
-
-  // Implementation of PolicyService::Observer:
-  virtual void OnPolicyUpdated(const PolicyNamespace& ns,
-                               const PolicyMap& previous,
-                               const PolicyMap& current) OVERRIDE;
-
- private:
-  typedef std::map<std::string, UpdateCallback> CallbackMap;
-
-  PolicyService* policy_service_;
-  PolicyNamespace ns_;
-  CallbackMap callback_map_;
-
-  DISALLOW_COPY_AND_ASSIGN(PolicyChangeRegistrar);
-};
-
-}  // namespace policy
-
-#endif  // CHROME_BROWSER_POLICY_POLICY_SERVICE_H_