Oilpan: Move the EventListener hierarchy to Oilpan's heap

Source/web/WebViewImpl.cpp

Index: Source/web/WebViewImpl.cpp
diff --git a/Source/web/WebViewImpl.cpp b/Source/web/WebViewImpl.cpp
index 0ea604cb6c51abeec3a85071eff36d4bd5fe839b..ff095b21e8c3f278e42a72b72f82fe26e9f88374 100644
--- a/Source/web/WebViewImpl.cpp
+++ b/Source/web/WebViewImpl.cpp
@@ -272,9 +272,9 @@ UserGestureNotifier::~UserGestureNotifier()
 
 class EmptyEventListener final : public EventListener {
 public:
-    static PassRefPtr<EmptyEventListener> create()
+    static PassRefPtrWillBeRawPtr<EmptyEventListener> create()
     {
-        return adoptRef(new EmptyEventListener());
+        return adoptRefWillBeNoop(new EmptyEventListener());
     }
 
     bool operator==(const EventListener& other) override