Add [WillBeGarbageCollected] to Event.idl

Source/core/events/GestureEvent.cpp

Index: Source/core/events/GestureEvent.cpp
diff --git a/Source/core/events/GestureEvent.cpp b/Source/core/events/GestureEvent.cpp
index 645b72a41ca4e0aaa04473378caa5a629625c352..b0f127d99a46ae75ec62a6a1dfae35ef8741d3b2 100644
--- a/Source/core/events/GestureEvent.cpp
+++ b/Source/core/events/GestureEvent.cpp
@@ -30,7 +30,7 @@
 
 namespace WebCore {
 
-PassRefPtr<GestureEvent> GestureEvent::create(PassRefPtr<AbstractView> view, const PlatformGestureEvent& event)
+PassRefPtrWillBeRawPtr<GestureEvent> GestureEvent::create(PassRefPtr<AbstractView> view, const PlatformGestureEvent& event)
 {
     AtomicString eventType;
     float deltaX = 0;
@@ -65,7 +65,7 @@ PassRefPtr<GestureEvent> GestureEvent::create(PassRefPtr<AbstractView> view, con
     default:
         return nullptr;
     }
-    return adoptRef(new GestureEvent(eventType, view, event.globalPosition().x(), event.globalPosition().y(), event.position().x(), event.position().y(), event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey(), deltaX, deltaY));
+    return adoptRefCountedWillBeRefCountedGarbageCollected(new GestureEvent(eventType, view, event.globalPosition().x(), event.globalPosition().y(), event.position().x(), event.position().y(), event.ctrlKey(), event.altKey(), event.shiftKey(), event.metaKey(), deltaX, deltaY));
 }
 
 const AtomicString& GestureEvent::interfaceName() const