Oilpan: move LiveNodeList collections to the heap.

Source/core/events/Event.cpp

Index: Source/core/events/Event.cpp
diff --git a/Source/core/events/Event.cpp b/Source/core/events/Event.cpp
index 205ae2b828d3de4f2911ece1104b3dafc939968f..3624f019be46e4a876e580bcc4cf08cedbe6775f 100644
--- a/Source/core/events/Event.cpp
+++ b/Source/core/events/Event.cpp
@@ -216,7 +216,7 @@ EventPath& Event::ensureEventPath()
     return *m_eventPath;
 }
 
-PassRefPtr<NodeList> Event::path() const
+PassRefPtrWillBeRawPtr<NodeList> Event::path() const
 {
     if (!m_currentTarget || !m_currentTarget->toNode())
         return StaticNodeList::createEmpty();