Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/shadow/ShadowRoot.cpp

Index: Source/core/dom/shadow/ShadowRoot.cpp
diff --git a/Source/core/dom/shadow/ShadowRoot.cpp b/Source/core/dom/shadow/ShadowRoot.cpp
index e7dcc984865024fc57d1a6ff573ea073cf93abaa..990c5891bd376adc344d9773ea0a3ee2dc3d5caa 100644
--- a/Source/core/dom/shadow/ShadowRoot.cpp
+++ b/Source/core/dom/shadow/ShadowRoot.cpp
@@ -68,10 +68,12 @@ ShadowRoot::~ShadowRoot()
     ASSERT(!m_prev);
     ASSERT(!m_next);
 
+#if !ENABLE(OILPAN)
     if (m_shadowRootRareData && m_shadowRootRareData->styleSheets())
         m_shadowRootRareData->styleSheets()->detachFromDocument();
 
     document().styleEngine()->didRemoveShadowRoot(this);

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

I wonder why these lines are not written in ShadowRoot::removedFrom(). Probably
do we need to add these lines in ShadowRoot::removedFrom() for #if
ENABLE(OILPAN)?

A better approach would be to just move these lines to
ShadowRoot::removedFrom(). Then we don't need to use #if.

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

No, we shouldn't have this in removedFrom. We should never call any of these
with Oilpan. The style sheet list and the document now live and die together
(strong pointers in both directions) and the shadow root collection in the style
engine is weak so that part is taken care of with weak processing.

+#endif
 
     // We cannot let ContainerNode destructor call willBeDeletedFromDocument()
     // for this ShadowRoot instance because TreeScope destructor
@@ -230,7 +232,7 @@ ShadowRootRareData* ShadowRoot::ensureShadowRootRareData()
     if (m_shadowRootRareData)
         return m_shadowRootRareData.get();
 
-    m_shadowRootRareData = adoptPtr(new ShadowRootRareData);
+    m_shadowRootRareData = adoptPtrWillBeNoop(new ShadowRootRareData);
     return m_shadowRootRareData.get();
 }
 
@@ -333,4 +335,11 @@ StyleSheetList* ShadowRoot::styleSheets()
     return m_shadowRootRareData->styleSheets();
 }
 
+void ShadowRoot::trace(Visitor* visitor)
+{
+    visitor->trace(m_shadowRootRareData);
+    TreeScope::trace(visitor);
+    DocumentFragment::trace(visitor);
+}
+
 }