Expose the chromium waterfall in sheriff-o-matic.

Tools/GardeningServer/ui/ct-failure-grouper.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-failure-grouper" attributes="failures groups">
-  <script>
-    Polymer({
-      failures: [],
-      groups: [],
-
-      failureComparator: function(a, b) {
-        return a.testName < b.testName;
-      },
-
-      failuresChanged: function() {
-        var map = {};
-        for (var i = 0; i < this.failures.length; ++i) {
-          var failureAnalysis = this.failures[i];
-          var key = failureAnalysis.newestPassingRevision + "+" + failureAnalysis.oldestFailingRevision;
-          if (!(key in map))
-            map[key] = [];
-          map[key].push(failureAnalysis);
-        }
-
-        this.groups = [];
-        var keys = Object.getOwnPropertyNames(map).sort();
-        for (var i = 0; i < keys.length; ++i) {
-          var key = keys[i];
-          this.groups[i] = map[key].sort(this.failureComparator.bind(this));
-        }
-      },
-    });
-  </script>
-</polymer-element>