Add experimental extension APIs to notify about wakeup and screen unlock

chrome/browser/chromeos/accessibility/system_event_observer.h

Index: chrome/browser/chromeos/accessibility/system_event_observer.h
diff --git a/chrome/browser/chromeos/accessibility/system_event_observer.h b/chrome/browser/chromeos/accessibility/system_event_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..82fcb6eaefd7963f8337d6ea8afae169a6c57962
--- /dev/null
+++ b/chrome/browser/chromeos/accessibility/system_event_observer.h
@@ -0,0 +1,54 @@
+// 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_CHROMEOS_ACCESSIBILITY_SYSTEM_EVENT_OBSERVER_H_
+#define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_SYSTEM_EVENT_OBSERVER_H_
+#pragma once
+
+#include "chrome/browser/chromeos/cros/power_library.h"
+#include "chrome/browser/chromeos/cros/screen_lock_library.h"
+
+namespace chromeos {
+namespace accessibility {
+
+// A singleton class to observe system events like wake up from sleep and
+// screen unlock.
+class SystemEventObserver : public PowerLibrary::Observer,
+                            public ScreenLockLibrary::Observer {
+ public:
+  virtual ~SystemEventObserver();
+
+  // PowerLibrary::Observer override.
+  virtual void SystemResumed() OVERRIDE;
+
+  // ScreenLockLibrary::Observer override.
+  virtual void LockScreen(ScreenLockLibrary* screen_lock_library) OVERRIDE;
+
+  // ScreenLockLibrary::Observer override.
+  virtual void UnlockScreen(ScreenLockLibrary* screen_lock_library) OVERRIDE;
+
+  // ScreenLockLibrary::Observer override.
+  virtual void UnlockScreenFailed(ScreenLockLibrary* screen_lock_library)
+      OVERRIDE;
+
+  // Creates the global SystemEventObserver instance.
+  static void Initialize();
+
+  // Returns a pointer to the global SystemEventObserver instance.
+  // Initialize() should already have been called.
+  static SystemEventObserver* GetInstance();
+
+  // Destroys the global SystemEventObserver Instance.
+  static void Shutdown();
+
+ private:
+  SystemEventObserver();
+
+  DISALLOW_COPY_AND_ASSIGN(SystemEventObserver);
+};
+
+}  // namespace accessibility
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_SYSTEM_EVENT_OBSERVER_H_