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

Source/web/WebDOMEvent.cpp

Index: Source/web/WebDOMEvent.cpp
diff --git a/Source/web/WebDOMEvent.cpp b/Source/web/WebDOMEvent.cpp
index eb70c33c240c55d0f2fc2835156eaa3d1197ba04..87a97c121e19f717d0e0ce61d44c6c7ddb06d532 100644
--- a/Source/web/WebDOMEvent.cpp
+++ b/Source/web/WebDOMEvent.cpp
@@ -56,12 +56,12 @@ void WebDOMEvent::assign(const WTF::PassRefPtr<WebDOMEventPrivate>& event)
     m_private = event;
 }
 
-WebDOMEvent::WebDOMEvent(const WTF::PassRefPtr<WebCore::Event>& event)
+WebDOMEvent::WebDOMEvent(const PassRefPtrWillBeRawPtr<WebCore::Event>& event)
     : m_private(event)
 {
 }
 
-WebDOMEvent::operator WTF::PassRefPtr<WebCore::Event>() const
+PassRefPtrWillBeRawPtr<WebCore::Event> WebDOMEvent::getValue() const
 {
     return m_private.get();
 }