| Index: tracing/tracing/ui/tracks/device_track.html | 
| diff --git a/tracing/tracing/ui/tracks/device_track.html b/tracing/tracing/ui/tracks/device_track.html | 
| index dbf38cd5ae0a00009fa10880f7d19f49a0af739c..c29086490f985678599769abd1b79d8c8b7796a8 100644 | 
| --- a/tracing/tracing/ui/tracks/device_track.html | 
| +++ b/tracing/tracing/ui/tracks/device_track.html | 
| @@ -32,7 +32,7 @@ tr.exportTo('tr.ui.tracks', function() { | 
| decorate: function(viewport) { | 
| ContainerTrack.prototype.decorate.call(this, viewport); | 
|  | 
| -      this.classList.add('device-track'); | 
| +      Polymer.dom(this).classList.add('device-track'); | 
| this.device_ = undefined; | 
| this.powerSeriesTrack_ = undefined; | 
| }, | 
|  |