Cleanup: Add more conversion helpers for usage.

Source/modules/device_orientation/DeviceOrientationEvent.h

Index: Source/modules/device_orientation/DeviceOrientationEvent.h
diff --git a/Source/modules/device_orientation/DeviceOrientationEvent.h b/Source/modules/device_orientation/DeviceOrientationEvent.h
index 6d27e42803917b4899ce689794bb5910dd3aa636..bec04107393a626afcef9046f13190787f8bf34a 100644
--- a/Source/modules/device_orientation/DeviceOrientationEvent.h
+++ b/Source/modules/device_orientation/DeviceOrientationEvent.h
@@ -62,6 +62,12 @@ private:
     RefPtr<DeviceOrientationData> m_orientation;
 };
 
+inline DeviceOrientationEvent* toDeviceOrientationEvent(Event* event)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!event || event->interfaceName() == EventNames::deviceorientation);

[tkent, 2013/10/10 01:51:13]

EventNames::deviceorientation should be
eventNames().interfaceForDeviceOrientationEvent.

+    return static_cast<DeviceOrientationEvent*>(event);
+}
+
 } // namespace WebCore
 
 #endif // DeviceOrientationEvent_h