| Index: tracing/tracing/ui/tracks/multi_row_track.html | 
| diff --git a/tracing/tracing/ui/tracks/multi_row_track.html b/tracing/tracing/ui/tracks/multi_row_track.html | 
| index 04637ef2d2ae3dee30a63220237cbfb60e1281be..6abbb6b321973e4a1182b831a37372df0dfd7636 100644 | 
| --- a/tracing/tracing/ui/tracks/multi_row_track.html | 
| +++ b/tracing/tracing/ui/tracks/multi_row_track.html | 
| @@ -178,10 +178,10 @@ tr.exportTo('tr.ui.tracks', function() { | 
| }, | 
|  | 
| updateHeadingAndTooltip_: function() { | 
| -      if (!this.firstChild) | 
| +      if (!Polymer.dom(this).firstChild) | 
| return; | 
| -      this.firstChild.heading = this.heading_; | 
| -      this.firstChild.tooltip = this.tooltip_; | 
| +      Polymer.dom(this).firstChild.heading = this.heading_; | 
| +      Polymer.dom(this).firstChild.tooltip = this.tooltip_; | 
| }, | 
|  | 
| /** | 
|  |