[oilpan] Make the oilpan branch build on Mac.

Source/core/dom/TreeScope.cpp

Index: Source/core/dom/TreeScope.cpp
diff --git a/Source/core/dom/TreeScope.cpp b/Source/core/dom/TreeScope.cpp
index a1524bdc5a008eb1cdd523040da082dce84a0881..e055893d86cdd1787180b76ac39abe3126cc4016 100644
--- a/Source/core/dom/TreeScope.cpp
+++ b/Source/core/dom/TreeScope.cpp
@@ -81,7 +81,6 @@ TreeScope::TreeScope(const Handle<ContainerNode>& rootNode, const Handle<Documen
 TreeScope::TreeScope(const Handle<Document>& document)
     : m_rootNode(document)
     , m_documentScope(document)
-    , m_parentTreeScope(0)
     , m_idTargetObserverRegistry(IdTargetObserverRegistry::create())
 {
     ASSERT(document);
@@ -89,9 +88,6 @@ TreeScope::TreeScope(const Handle<Document>& document)
 }
 
 TreeScope::TreeScope()
-    : m_rootNode(0)
-    , m_documentScope(0)
-    , m_parentTreeScope(0)
 {
 }