Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/svg/SVGSVGElement.cpp

Index: Source/core/svg/SVGSVGElement.cpp
diff --git a/Source/core/svg/SVGSVGElement.cpp b/Source/core/svg/SVGSVGElement.cpp
index 615d4c859d730632b7cafd58883ac7cf112f2864..cafe0745c66901ae555c3a327cc66ceddad069b4 100644
--- a/Source/core/svg/SVGSVGElement.cpp
+++ b/Source/core/svg/SVGSVGElement.cpp
@@ -96,11 +96,15 @@ SVGSVGElement::~SVGSVGElement()
     if (m_viewSpec)
         m_viewSpec->detachContextElement();
 
+#if !ENABLE(OILPAN)
     // There are cases where removedFromDocument() is not called.
     // see ContainerNode::removeAllChildren, called by its destructor.
+    // With Oilpan, either removedFrom is called or the document
+    // is dead as well and there is no reason to clear the extensions.
     document().accessSVGExtensions().removeTimeContainer(this);
 
     ASSERT(inDocument() || !accessDocumentSVGExtensions().isSVGRootWithRelativeLengthDescendents(this));
+#endif
 }
 
 const AtomicString& SVGSVGElement::contentScriptType() const