Oilpan: Replace RefPtrs to Node and its subclasses in core/events/ with Oilpan transition types.

Source/core/events/NodeEventContext.cpp

Index: Source/core/events/NodeEventContext.cpp
diff --git a/Source/core/events/NodeEventContext.cpp b/Source/core/events/NodeEventContext.cpp
index e422cceaf80797f268958cacc1e895a08565bb2b..f520f5ae4e7eb3940f8df9b4a251995a232e3d86 100644
--- a/Source/core/events/NodeEventContext.cpp
+++ b/Source/core/events/NodeEventContext.cpp
@@ -35,7 +35,7 @@
 
 namespace WebCore {
 
-NodeEventContext::NodeEventContext(PassRefPtr<Node> node, PassRefPtr<EventTarget> currentTarget)
+NodeEventContext::NodeEventContext(PassRefPtrWillBeRawPtr<Node> node, PassRefPtr<EventTarget> currentTarget)
     : m_node(node)
     , m_currentTarget(currentTarget)
 {
@@ -46,6 +46,11 @@ NodeEventContext::~NodeEventContext()
 {
 }
 
+void NodeEventContext::trace(Visitor* visitor)
+{
+    visitor->trace(m_node);
+}
+
 void NodeEventContext::handleLocalEvents(Event* event) const
 {
     if (touchEventContext()) {