fixed bug 90274 r=shliang sr=hewitt selected folder name in mac classic not showing up

themes/classic/global/mac/tree.css

@@ -38,11 +38,11 @@ treeitem > treerow {
 }
 
 treeitem[selected="true"] > treerow { 
-	color: #000000;
+	color: HighlightText;
 	background-color: Highlight;
 }
 treeitem[dd-dropon="true"] > treerow { 
-	color: #000000;
+	color: HighlightText;
 	background-color: Highlight;
 }