Prepare SMILTimeContainer for oilpan

Source/core/svg/SVGElementRareData.h

Index: Source/core/svg/SVGElementRareData.h
diff --git a/Source/core/svg/SVGElementRareData.h b/Source/core/svg/SVGElementRareData.h
index bca640791b94e84fa8b4d87fe2db414dac794bb4..e4fa75d096d03575ef5022968c90319cf298b2c9 100644
--- a/Source/core/svg/SVGElementRareData.h
+++ b/Source/core/svg/SVGElementRareData.h
@@ -43,7 +43,7 @@ public:
         : m_cursorElement(nullptr)
 #endif
         , m_cursorImageValue(nullptr)
-        , m_correspondingElement(0)
+        , m_correspondingElement(nullptr)
         , m_instancesUpdatesBlocked(false)
         , m_useOverrideComputedStyle(false)
         , m_needsOverrideComputedStyleUpdate(false)
@@ -113,6 +113,7 @@ public:
     {
         visitor->trace(m_animatedSMILStyleProperties);
         visitor->trace(m_elementInstances);
+        visitor->trace(m_correspondingElement);
         visitor->registerWeakMembers<SVGElementRareData, &SVGElementRareData::processWeakMembers>(this);
     }
 
@@ -155,7 +156,7 @@ private:
     WillBeHeapHashSet<RawPtrWillBeWeakMember<SVGElement> > m_elementInstances;
     RawPtrWillBeWeakMember<SVGCursorElement> m_cursorElement;
     RawPtrWillBeWeakMember<CSSCursorImageValue> m_cursorImageValue;
-    SVGElement* m_correspondingElement;
+    RawPtrWillBeMember<SVGElement> m_correspondingElement;

[haraken, 2014/05/26 08:27:27]

Just to confirm: This should be a WeakMember conceptually, but doesn't need to
be weak because it's explicitly cleared out. Right?

[haraken, 2014/05/26 08:43:28]

Discussed offline. This is a strong member both conceptually and practically. So
using a member completely makes sense.

What we don't still understand is why this is not a RefPtr in the pre-oilpan
world, but this seems to be an actual bug (kouhei is saying that there are crash
reports about it).

     bool m_instancesUpdatesBlocked : 1;
     bool m_useOverrideComputedStyle : 1;
     bool m_needsOverrideComputedStyleUpdate : 1;