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

Source/modules/screen_orientation/ScreenOrientationController.cpp

Index: Source/modules/screen_orientation/ScreenOrientationController.cpp
diff --git a/Source/modules/screen_orientation/ScreenOrientationController.cpp b/Source/modules/screen_orientation/ScreenOrientationController.cpp
index bc0564bc05c15bace8d11c0b2622735bd1faaa26..b469dd755d273671e64b9cd4e331ef4d479ccee1 100644
--- a/Source/modules/screen_orientation/ScreenOrientationController.cpp
+++ b/Source/modules/screen_orientation/ScreenOrientationController.cpp
@@ -10,6 +10,7 @@
 #include "core/frame/LocalFrame.h"
 #include "core/page/Page.h"
 #include "modules/screen_orientation/ScreenOrientation.h"
+#include "modules/screen_orientation/ScreenOrientationDispatcher.h"
 #include "platform/LayoutTestSupport.h"
 #include "platform/PlatformScreen.h"
 #include "public/platform/WebScreenOrientationClient.h"
@@ -40,7 +41,7 @@ ScreenOrientationController* ScreenOrientationController::from(LocalFrame& frame
 }
 
 ScreenOrientationController::ScreenOrientationController(LocalFrame& frame, blink::WebScreenOrientationClient* client)
-    : PageLifecycleObserver(frame.page())
+    : PlatformEventController(frame.page())
     , m_client(client)
     , m_frame(frame)
     , m_dispatchEventTimer(this, &ScreenOrientationController::dispatchEventTimerFired)
@@ -96,6 +97,8 @@ void ScreenOrientationController::updateOrientation()
 
 void ScreenOrientationController::pageVisibilityChanged()
 {
+    notifyDispatcher();
+
     if (!m_orientation || !page() || page()->visibilityState() != PageVisibilityStateVisible)
         return;
 
@@ -147,6 +150,7 @@ void ScreenOrientationController::setOrientation(ScreenOrientation* orientation)
     m_orientation = orientation;
     if (m_orientation)
         updateOrientation();
+    notifyDispatcher();
 }
 
 void ScreenOrientationController::lock(blink::WebScreenOrientationLockType orientation, blink::WebLockOrientationCallback* callback)
@@ -173,6 +177,34 @@ void ScreenOrientationController::dispatchEventTimerFired(Timer<ScreenOrientatio
     m_orientation->dispatchEvent(Event::create(EventTypeNames::change));
 }
 
+void ScreenOrientationController::didUpdateData()
+{
+    // Do nothing.
+}
+
+void ScreenOrientationController::registerWithDispatcher()
+{
+    ScreenOrientationDispatcher::instance().addController(this);
+}
+
+void ScreenOrientationController::unregisterWithDispatcher()
+{
+    ScreenOrientationDispatcher::instance().removeController(this);
+}
+
+bool ScreenOrientationController::hasLastData()
+{
+    return true;
+}
+
+void ScreenOrientationController::notifyDispatcher()
+{
+    if (m_orientation && page()->visibilityState() == PageVisibilityStateVisible)
+        startUpdating();
+    else
+        stopUpdating();
+}
+
 void ScreenOrientationController::trace(Visitor* visitor)
 {
     visitor->trace(m_orientation);