Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/html/HTMLStyleElement.cpp

Index: Source/core/html/HTMLStyleElement.cpp
diff --git a/Source/core/html/HTMLStyleElement.cpp b/Source/core/html/HTMLStyleElement.cpp
index 76f96d2f4609ea04fd568022e84e0864520628f0..d614c11d6da0b9282a2f44c0669640cef374505a 100644
--- a/Source/core/html/HTMLStyleElement.cpp
+++ b/Source/core/html/HTMLStyleElement.cpp
@@ -58,7 +58,9 @@ HTMLStyleElement::~HTMLStyleElement()
 {
     // During tear-down, willRemove isn't called, so m_scopedStyleRegistrationState may still be RegisteredAsScoped or RegisteredInShadowRoot here.
     // Therefore we can't ASSERT(m_scopedStyleRegistrationState == NotRegistered).
+#if !ENABLE(OILPAN)
     StyleElement::clearDocumentData(document(), this);

[haraken, 2014/04/25 14:30:32]

clearDocumentData() is calling m_sheet->clearOwnerNode(). I think we still need
to call that in oilpan because the StyleSheet can outlive the HTMLStyleElement.

[Mads Ager (chromium), 2014/04/28 09:45:21]

Good point. The StyleSheet and its owner should live and die together with
Oilpan. However, there are a couple of owners that we need to move to the heap
in order to make that happen. Added the clearing of m_sheet's owner for Oilpan
with a comment that it should be removed when the sheet has a strong pointer to
its owner node.

+#endif
 
     styleLoadEventSender().cancelEvent(this);
 }