Oilpan: Replace most of RefPtrs for Event objects with oilpan's transition types

Source/web/tests/CustomEventTest.cpp

Index: Source/web/tests/CustomEventTest.cpp
diff --git a/Source/web/tests/CustomEventTest.cpp b/Source/web/tests/CustomEventTest.cpp
index 8d75e40eb44e56fbf97211e5a7d0452b44ab695d..a1defb5f8eb322c92957b9cb503ebb9fbe98ae22 100644
--- a/Source/web/tests/CustomEventTest.cpp
+++ b/Source/web/tests/CustomEventTest.cpp
@@ -104,9 +104,7 @@ TEST(CustomEventTest, InitWithSerializedScriptValue)
     URLTestHelpers::registerMockedURLFromBaseURL(WebString::fromUTF8(baseURL.c_str()), WebString::fromUTF8(path.c_str()));
     FrameTestHelpers::WebViewHelper webViewHelper;
     WebFrameImpl* frame = toWebFrameImpl(webViewHelper.initializeAndLoad(baseURL + path)->mainFrame());
-
-    // FIXME: oilpan: Remove PassRefPtr<Event>() once we support PassRefPtrWillBeRawPtr in WebDOMEvent.
-    WebDOMEvent event = PassRefPtr<Event>(frame->frame()->document()->createEvent("CustomEvent", IGNORE_EXCEPTION));
+    WebDOMEvent event = frame->frame()->document()->createEvent("CustomEvent", IGNORE_EXCEPTION);
     WebDOMCustomEvent customEvent = event.to<WebDOMCustomEvent>();
 
     v8::Isolate* isolate = toIsolate(frame->frame());