Fix mac bot specific performance regression by reverting set of patches

Source/core/dom/Node.h

Index: Source/core/dom/Node.h
diff --git a/Source/core/dom/Node.h b/Source/core/dom/Node.h
index a2099397b6f899670f62617dcb860a89d0fa5128..ada8a6f27d749211161a7c97adb9be4a9fe42380 100644
--- a/Source/core/dom/Node.h
+++ b/Source/core/dom/Node.h
@@ -171,9 +171,6 @@ public:
     virtual String nodeValue() const;
     virtual void setNodeValue(const String&);
     virtual NodeType nodeType() const = 0;
-    // FIXME: We should get rid of parentNode() usage and replace with parent()
-    // to bring us inline with the API of other tree structures in the codebase.
-    ContainerNode* parent() const { return parentNode(); }
     ContainerNode* parentNode() const;
     Element* parentElement() const;
     Node* previousSibling() const { return m_previous; }