Add [WillBeGarbageCollected] to Event.idl

Source/core/events/ResourceProgressEvent.h

Index: Source/core/events/ResourceProgressEvent.h
diff --git a/Source/core/events/ResourceProgressEvent.h b/Source/core/events/ResourceProgressEvent.h
index 596baf13b05c58d5b8facc99a094ad9c210d0b5f..a0ec9f4e150a515aad525132848f55ffda35c119 100644
--- a/Source/core/events/ResourceProgressEvent.h
+++ b/Source/core/events/ResourceProgressEvent.h
@@ -44,13 +44,13 @@ namespace WebCore {
 // EventInit pattern for Event construction.
 class ResourceProgressEvent FINAL : public ProgressEvent {
 public:
-    static PassRefPtr<ResourceProgressEvent> create()
+    static PassRefPtrWillBeRawPtr<ResourceProgressEvent> create()
     {
-        return adoptRef(new ResourceProgressEvent);
+        return adoptRefWillBeRefCountedGarbageCollected(new ResourceProgressEvent);
     }
-    static PassRefPtr<ResourceProgressEvent> create(const AtomicString& type, bool lengthComputable, unsigned long long loaded, unsigned long long total, const String& url)
+    static PassRefPtrWillBeRawPtr<ResourceProgressEvent> create(const AtomicString& type, bool lengthComputable, unsigned long long loaded, unsigned long long total, const String& url)
     {
-        return adoptRef(new ResourceProgressEvent(type, lengthComputable, loaded, total, url));
+        return adoptRefWillBeRefCountedGarbageCollected(new ResourceProgressEvent(type, lengthComputable, loaded, total, url));
     }
 
     const String& url() const;