Migrate child element manipulation, innerHTML, classList, attributes,

tracing/tracing/ui/base/ui.html

Index: tracing/tracing/ui/base/ui.html
diff --git a/tracing/tracing/ui/base/ui.html b/tracing/tracing/ui/base/ui.html
index 20c1bd4471db1f42376dfa59dd34b8bdc9b0d5cd..b484ef26b020e6d13d1c7d38c3da76a7a473dd56 100644
--- a/tracing/tracing/ui/base/ui.html
+++ b/tracing/tracing/ui/base/ui.html
@@ -152,10 +152,10 @@ tr.exportTo('tr.ui.b', function() {
       return false;
 
     var cur = el;
-    while (cur.parentNode) {
+    while (Polymer.dom(cur).parentNode) {
       if (cur == potentialParent)
         return true;
-      cur = cur.parentNode;
+      cur = Polymer.dom(cur).parentNode;
     }
     return false;
   };