| 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; | 
| }; | 
|  |