Don't add extra items to sheriff-o-matic history.

Tools/GardeningServer/ui/ct-embedded-flakiness-dashboard.html

 <!--
 Copyright 2014 The Chromium Authors. All rights reserved.
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 -->
 
 <polymer-element name="ct-embedded-flakiness-dashboard" attributes="test tree">
   <template>
     <style>
       :host {
@@ skipping 14 matching lines @@
       ready: function() {
         window.addEventListener('message', function(event) {
           if (event.data.command != 'heightChanged')
             return;
 
           this.$.iframe.style.height = event.data.height + 'px';
         }.bind(this));
       },
 
       testChanged: function() {
-        this.$.iframe.src = this.test.embeddedFlakinessDashboardURL(this.tree);
+        this.$.iframe.contentWindow.location.replace(this.test.embeddedFlakinessDashboardURL(this.tree));

[ojan, 2014/08/16 01:40:56]

Add a comment explaining why we use replace?

Also, does this really work? Can you access location on a cross-origin iframe?

[michaelpg, 2014/08/16 02:05:45]

It works, but it's weird. You can get a reference to the iframe's window, but
you can't enumerate the window's keys. However, you can call
window.location.replace, and you can even set window.location.href (but trying
to read that property throws a security error).

On my machine it successfully serves pages from
https://test-results.appspot.com.

I think it comes from this:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

       },
 
     });
   </script>
 </polymer-element>