Oilpan: have PendingScripts trace their script elements.

Source/core/dom/PendingScript.cpp

Index: Source/core/dom/PendingScript.cpp
diff --git a/Source/core/dom/PendingScript.cpp b/Source/core/dom/PendingScript.cpp
index b448c8bd9bfd823a5d7255426a9dcd745171bb04..d29146cb70878a563790fdd475be3044418391f2 100644
--- a/Source/core/dom/PendingScript.cpp
+++ b/Source/core/dom/PendingScript.cpp
@@ -35,7 +35,7 @@ PendingScript::~PendingScript()
 {
 }
 
-PassRefPtr<Element> PendingScript::releaseElementAndClear()
+PassRefPtrWillBeRawPtr<Element> PendingScript::releaseElementAndClear()
 {
     setScriptResource(0);
     m_watchingForLoad = false;
@@ -52,4 +52,9 @@ void PendingScript::notifyFinished(Resource*)
 {
 }
 
+void PendingScript::trace(Visitor* visitor)
+{
+    visitor->trace(m_element);
+}
+
 }