Migrate child element manipulation, innerHTML, classList, attributes,

tracing/tracing/ui/base/resize_sensor.html

Index: tracing/tracing/ui/base/resize_sensor.html
diff --git a/tracing/tracing/ui/base/resize_sensor.html b/tracing/tracing/ui/base/resize_sensor.html
index 6c1dc1825ce591340b1bdd00e82e815342617927..6eb63b79bc15612cfa0af808ace8a4ecc7352f46 100644
--- a/tracing/tracing/ui/base/resize_sensor.html
+++ b/tracing/tracing/ui/base/resize_sensor.html
@@ -40,7 +40,7 @@ found in the LICENSE file.
       // ResizeSensor appends a div to this.$.container. That div must be a
       // direct sibling of <content>.
       // ResizeSensor's first argument must be a Node, so it cannot be
-      // this.shadowRoot.
+      // this.root.
     },
 
     onResize_: function() {