Add failed builders to sheriff-o-matic.

Tools/GardeningServer/ui/ct-failing-builders.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.
+-->
+
+<link rel="import" href="ct-builder.html">
+
+<!-- Lists builders that are failing and the problematic steps. -->
+<polymer-element name="ct-failing-builders" attributes="builders">
+  <template>
+    <style>
+      :host {
+        display: block;
+        font-size: 0;
+      }
+
+      ct-builder {
+        display: inline-block;
+        margin: 0 5px 2px 0;
+      }
+    </style>
+    <template repeat="{{ builder in builders|keys }}">
+      <ct-builder builderName="{{ builder }}" steps="{{ builders[builder] }}">
+      </ct-builder>
+    </template>
+  </template>
+  <script>
+    Polymer({
+      builders: {},
+
+      keys: function(obj) {
+        return Object.keys(obj);
+      },
+    });
+  </script>
+</polymer-element>