Make Screen Orientation use Platform Events in order to handle polling.

Source/modules/screen_orientation/ScreenOrientationController.h

 // Copyright 2014 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 ScreenOrientationController_h
 #define ScreenOrientationController_h
 
-#include "core/page/PageLifecycleObserver.h"
+#include "core/frame/PlatformEventController.h"
 #include "platform/Supplementable.h"
 #include "platform/Timer.h"
 #include "public/platform/WebLockOrientationCallback.h"
 #include "public/platform/WebScreenOrientationLockType.h"
 #include "public/platform/WebScreenOrientationType.h"
 
 namespace blink {
 class WebScreenOrientationClient;
 }
 
 namespace blink {
 
 class FrameView;
 class ScreenOrientation;
 
 class ScreenOrientationController FINAL
     : public NoBaseWillBeGarbageCollectedFinalized<ScreenOrientationController>
     , public WillBeHeapSupplement<LocalFrame>
-    , public PageLifecycleObserver {
+    , public PlatformEventController {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ScreenOrientationController);
     WTF_MAKE_NONCOPYABLE(ScreenOrientationController);
 public:
     virtual ~ScreenOrientationController();
 
     virtual void persistentHostHasBeenDestroyed() OVERRIDE;
 
     void setOrientation(ScreenOrientation*);
     void notifyOrientationChanged();
 
     void lock(blink::WebScreenOrientationLockType, blink::WebLockOrientationCallback*);
     void unlock();
 
     const LocalFrame& frame() const;
 
     static void provideTo(LocalFrame&, blink::WebScreenOrientationClient*);
     static ScreenOrientationController* from(LocalFrame&);
     static const char* supplementName();
 
     virtual void trace(Visitor*);
 
 private:
     explicit ScreenOrientationController(LocalFrame&, blink::WebScreenOrientationClient*);
     static blink::WebScreenOrientationType computeOrientation(FrameView*);
 
-    // Inherited from PageLifecycleObserver.
+    // Inherited from PlatformEventController.
+    virtual void didUpdateData() OVERRIDE;
+    virtual void registerWithDispatcher() OVERRIDE;
+    virtual void unregisterWithDispatcher() OVERRIDE;
+    virtual bool hasLastData() OVERRIDE;
     virtual void pageVisibilityChanged() OVERRIDE;
 
+    void notifyDispatcher();
+
     void updateOrientation();
 
     void dispatchEventTimerFired(Timer<ScreenOrientationController>*);
 
     PersistentWillBeMember<ScreenOrientation> m_orientation;
     blink::WebScreenOrientationClient* m_client;
     LocalFrame& m_frame;
     Timer<ScreenOrientationController> m_dispatchEventTimer;
 };
 
 } // namespace blink
 
 #endif // ScreenOrientationController_h