Add device policies to control accessibility settings on the login screen

chrome/browser/chromeos/policy/recommendation_restorer.h

Index: chrome/browser/chromeos/policy/recommendation_restorer.h
diff --git a/chrome/browser/chromeos/policy/recommendation_restorer.h b/chrome/browser/chromeos/policy/recommendation_restorer.h
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+// Copyright (c) 2013 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_CHROMEOS_POLICY_RECOMMENDATION_RESTORER_H_
+#define CHROME_BROWSER_CHROMEOS_POLICY_RECOMMENDATION_RESTORER_H_
+
+#include <string>
+
+#include "ash/wm/user_activity_observer.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/prefs/pref_change_registrar.h"
+#include "base/timer.h"
+#include "components/browser_context_keyed_service/browser_context_keyed_service.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+
+class Profile;
+
+namespace policy {
+
+// Observes a set of prefs in the login profile. If any of the prefs has a
+// recommended value, its user setting is cleared so that the recommendation can
+// take effect. This happens immediately when the login screen is shown, when
+// a session is being started and whenever recommended values change during a
+// user session. On the login screen, user settings are cleared when the user
+// becomes idle for one minute.
+class RecommendationRestorer : public BrowserContextKeyedService,
+                               public content::NotificationObserver,
+                               public ash::UserActivityObserver {
+ public:
+  explicit RecommendationRestorer(Profile* profile);
+  virtual ~RecommendationRestorer();
+
+  // BrowserContextKeyedService:
+  virtual void Shutdown() OVERRIDE;
+
+  // content::NotificationObserver:
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  // ash::UserActivityObserver::Observer:
+  virtual void OnUserActivity() OVERRIDE;
+
+  // If a recommended value and a user setting exist for |pref_name|, clears the
+  // user setting so that the recommended value can take effect. If
+  // |allow_delay| is |true| and the login screen is being shown, a timer is
+  // started that will clear the setting when the user becomes idle for one
+  // minute. Otherwise, the setting is cleared immediately.
+  void Restore(bool allow_delay, const std::string& pref_name);
+
+ private:
+  friend class RecommendationRestorerTest;
+
+  void RestoreAll();
+
+  void StartTimer();
+  void StopTimer();
+
+  PrefChangeRegistrar pref_change_registrar_;
+  content::NotificationRegistrar notification_registrar_;
+
+  bool logged_in_;
+
+  base::OneShotTimer<RecommendationRestorer> restore_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(RecommendationRestorer);
+};
+
+}  // namespace policy
+
+#endif  // CHROME_BROWSER_CHROMEOS_POLICY_RECOMMENDATION_RESTORER_H_