Added ConfigurationPolicyProvider::RefreshPolicies.

chrome/browser/policy/asynchronous_policy_loader.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_ASYNCHRONOUS_POLICY_LOADER_H_
 #define CHROME_BROWSER_POLICY_ASYNCHRONOUS_POLICY_LOADER_H_
 #pragma once
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time.h"
 #include "base/values.h"
 #include "chrome/browser/policy/asynchronous_policy_provider.h"
 #include "chrome/browser/policy/configuration_policy_provider.h"
 
 class MessageLoop;
 
 namespace policy {
 
 // Used by the implementation of asynchronous policy provider to manage the
 // tasks on the FILE thread that do the heavy lifting of loading policies.
 class AsynchronousPolicyLoader
     : public base::RefCountedThreadSafe<AsynchronousPolicyLoader> {
  public:
   AsynchronousPolicyLoader(AsynchronousPolicyProvider::Delegate* delegate,
                            int reload_interval_minutes);
 
-  // Triggers initial policy load, and installs |callback| as the callback to
-  // invoke on policy updates.
-  virtual void Init(const base::Closure& callback);
+  // Triggers initial policy load, and installs |default_callback| as the
+  // callback to invoke on policy updates that haven't been requested.
+  virtual void Init(const base::Closure& default_callback);
 
-  // Reloads policy, sending notification of changes if necessary. Must be
-  // called on the FILE thread. When |force| is true, the loader should do an
-  // immediate full reload.
-  virtual void Reload(bool force);
+  // Reloads policy and invokes |callback| on |origin_loop_| when done.
+  // The loader does a full reload immediately when |force| is true.
+  // |callback| is guaranteed to be eventually invoked, even if the loading
+  // fails. This method must be called on the FILE thread.
+  virtual void Reload(const base::Closure& callback, bool force);
 
   // Stops any pending reload tasks. Updates callbacks won't be performed
   // anymore once the loader is stopped.
   virtual void Stop();
 
   const DictionaryValue* policy() const { return policy_.get(); }
 
  protected:
   // AsynchronousPolicyLoader objects should only be deleted by
   // RefCountedThreadSafe.
   friend class base::RefCountedThreadSafe<AsynchronousPolicyLoader>;
   virtual ~AsynchronousPolicyLoader();
 
   // Schedules a call to UpdatePolicy on |origin_loop_|. Takes ownership of
   // |new_policy|.
-  void PostUpdatePolicyTask(DictionaryValue* new_policy);
+  void PostUpdatePolicyTask(const base::Closure& callback,
+                            DictionaryValue* new_policy);
 
   AsynchronousPolicyProvider::Delegate* delegate() {
     return delegate_.get();
   }
 
+  const base::Closure& default_callback() { return default_callback_; }
+
   // Performs start operations that must be performed on the FILE thread.
   virtual void InitOnFileThread();
 
   // Performs stop operations that must be performed on the FILE thread.
   virtual void StopOnFileThread();
 
   // Schedules a reload task to run when |delay| expires. Must be called on the
   // FILE thread.
-  void ScheduleReloadTask(const base::TimeDelta& delay);
+  void ScheduleReloadTask(const base::Closure& callback,
+                          const base::TimeDelta& delay);
 
   // Schedules a reload task to run after the number of minutes specified
   // in |reload_interval_minutes_|. Must be called on the FILE thread.
   void ScheduleFallbackReloadTask();
 
   void CancelReloadTask();
 
-  // Invoked from the reload task on the FILE thread.
-  void ReloadFromTask();
-
  private:
   friend class AsynchronousPolicyLoaderTest;
 
   // Finishes loader initialization after the threading system has been fully
   // intialized.
   void InitAfterFileThreadAvailable();
 
-  // Replaces the existing policy to value map with a new one, sending
-  // notification to the observers if there is a policy change. Must be called
-  // on |origin_loop_| so that it's safe to call back into the provider, which
-  // is not thread-safe. Takes ownership of |new_policy|.
-  void UpdatePolicy(DictionaryValue* new_policy);
+  // Replaces the existing policy to value map with a new one, and invokes
+  // |callback|. Must be called on |origin_loop_| so that it's safe to callback
+  // into the provider, which is not thread-safe. Takes ownership of
+  // |new_policy|.
+  void UpdatePolicy(const base::Closure& callback, DictionaryValue* new_policy);
 
   // Provides the low-level mechanics for loading policy.
   scoped_ptr<AsynchronousPolicyProvider::Delegate> delegate_;
 
   // Current policy.
   scoped_ptr<DictionaryValue> policy_;
 
   // Used to create and invalidate WeakPtrs on the FILE thread. These are only
   // used to post reload tasks that can be cancelled.
   base::WeakPtrFactory<AsynchronousPolicyLoader> weak_ptr_factory_;
 
   // The interval at which a policy reload will be triggered as a fallback.
-  const base::TimeDelta  reload_interval_;
+  const base::TimeDelta reload_interval_;
 
   // The message loop on which this object was constructed. Recorded so that
   // it's possible to call back into the non thread safe provider to fire the
   // notification.
   MessageLoop* origin_loop_;
 
   // True if Stop has been called.
   bool stopped_;
 
-  // Callback to invoke on policy updates.
-  base::Closure updates_callback_;
+  // Default callback to invoke on policy updates that weren't explicitly
+  // requested by the provider.
+  base::Closure default_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(AsynchronousPolicyLoader);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_ASYNCHRONOUS_POLICY_LOADER_H_