Improvements in performance.

content/shared/public/nsXULAtomList.h

@@ -62,6 +62,7 @@ XUL_ATOM(treecol, "treecol") // A column in the tree view
 XUL_ATOM(treecolgroup, "treecolgroup") // A column group in the tree view
 XUL_ATOM(treefoot, "treefoot") // The footer of the tree view
 XUL_ATOM(treepusher, "treepusher") // A column pusher (left or right) for the tree view
+XUL_ATOM(scrollbarlist, "scrollbarlist") // An atom for internal use by the tree view
 
 XUL_ATOM(open, "open") // Whether or not a menu, tree, etc. is open
 

layout/xul/base/src/nsTreeRowGroupFrame.cpp

@@ -563,8 +563,7 @@ nsTreeRowGroupFrame::GetFrameForPoint(const nsPoint& aPoint, nsIFrame** aFrame)
 NS_IMETHODIMP
 nsTreeRowGroupFrame::FirstChild(nsIAtom* aListName, nsIFrame** aFirstChild) const
 {
-  nsCOMPtr<nsIAtom> scrollList = dont_AddRef(NS_NewAtom("scrollbarlist"));
-  if (scrollList.get() == aListName) {
+  if (nsXULAtoms::scrollbarlist == aListName) {
     *aFirstChild = mScrollbarList.FirstChild();
     return NS_OK;
   }
@@ -580,7 +579,8 @@ nsTreeRowGroupFrame::GetAdditionalChildListName(PRInt32   aIndex,
   *aListName = nsnull;
 
   if (aIndex == 0) {
-    *aListName = NS_NewAtom("scrollbarlist"); // AddRefs
+    *aListName = nsXULAtoms::scrollbarlist;
+    NS_IF_ADDREF(*aListName);
   }
 
   return NS_OK;

layout/xul/content/src/nsXULAtomList.h

@@ -62,6 +62,7 @@ XUL_ATOM(treecol, "treecol") // A column in the tree view
 XUL_ATOM(treecolgroup, "treecolgroup") // A column group in the tree view
 XUL_ATOM(treefoot, "treefoot") // The footer of the tree view
 XUL_ATOM(treepusher, "treepusher") // A column pusher (left or right) for the tree view
+XUL_ATOM(scrollbarlist, "scrollbarlist") // An atom for internal use by the tree view
 
 XUL_ATOM(open, "open") // Whether or not a menu, tree, etc. is open