Changing policy while Chrome is running should refresh preferences without relaunching

chrome/browser/configuration_policy_provider_win.h

 // Copyright (c) 2010 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_CONFIGURATION_POLICY_PROVIDER_WIN_H_
 #define CHROME_BROWSER_CONFIGURATION_POLICY_PROVIDER_WIN_H_
 #pragma once
 
+#include "base/object_watcher.h"
+#include "base/scoped_ptr.h"
+#include "base/waitable_event.h"
 #include "chrome/browser/configuration_policy_store.h"
 #include "chrome/browser/configuration_policy_provider.h"
 
 // An implementation of |ConfigurationPolicyProvider| using the
 // mechanism provided by Windows Groups Policy. Policy decisions are
 // stored as values in a special section of the Windows Registry.
 // On a managed machine in a domain, this portion of the registry is
 // periodically updated by the Windows Group Policy machinery to contain
 // the latest version of the policy set by administrators.
 class ConfigurationPolicyProviderWin : public ConfigurationPolicyProvider {
  public:
+  // Keeps watch on Windows Group Policy notification event to trigger
+  // a policy reload when Group Policy changes.
+  class GroupPolicyChangeWatcher : public base::ObjectWatcher::Delegate {
+   public:
+    explicit GroupPolicyChangeWatcher(ConfigurationPolicyProvider* provider);
+    virtual ~GroupPolicyChangeWatcher() {}
+
+    virtual void OnObjectSignaled(HANDLE object);
+
+   private:
+    ConfigurationPolicyProvider* provider_;
+    base::WaitableEvent user_policy_changed_event_;
+    base::WaitableEvent machine_policy_changed_event_;
+    base::ObjectWatcher user_policy_watcher_;
+    base::ObjectWatcher machine_policy_watcher_;
+  };
+
   ConfigurationPolicyProviderWin();
   virtual ~ConfigurationPolicyProviderWin() { }
 
   // ConfigurationPolicyProvider method overrides:
   virtual bool Provide(ConfigurationPolicyStore* store);
 
  protected:
   // The sub key path for Chromium's Group Policy information in the
   // Windows registry.
   static const wchar_t kPolicyRegistrySubKey[];
 
  private:
+  scoped_ptr<GroupPolicyChangeWatcher> watcher_;
+
   // Methods to perfrom type-specific policy lookups in the registry.
   // HKLM is checked first, then HKCU.
   bool GetRegistryPolicyString(const wchar_t* value_name, string16* result);
   bool GetRegistryPolicyBoolean(const wchar_t* value_name, bool* result);
   bool GetRegistryPolicyInteger(const wchar_t* value_name, uint32* result);
 };
 
 #endif  // CHROME_BROWSER_CONFIGURATION_POLICY_PROVIDER_WIN_H_