config_service: add last import validation and tests

appengine/config_service/ui/src/config-ui/config-file-card.html

+<!--
+  Copyright 2017 The LUCI Authors. All rights reserved.
+  Use of this source code is governed under the Apache License, Version 2.0
+  that can be found in the LICENSE file.
+-->
+
+<link rel="import" href="../../bower_components/paper-item/paper-item.html">
+<link rel="import" href="../../bower_components/polymer/polymer.html">
+<link rel="import" href="../../bower_components/iron-icons/maps-icons.html">
+<link rel="import" href="../../bower_components/iron-flex-layout/iron-flex-layout.html">
+
+<dom-module id="config-file-card">
+  <template>
+    <style include="iron-flex iron-flex-alignment">
+      .center {
+        margin: auto;
+        width: 25%;
+        border-style: solid;
+        border-width: 2px;
+      }
+
+      iron-icon {
+        float: right;
+      }
+
+    </style>
+
+    <paper-item class="center">
+      <!-- TODO(cwpayton): Currently, each card contains a link to the
+      corresponding file in gitiles. We would like to pretty print the
+      contents of the file in the UI instead of externally linking. -->
+      <div class="horizontal layout wrap" style="width: 100%">
+        [[name]]
+        <iron-icon icon="icons:link" on-tap="_handleClick"></iron-icon>
+      </div>
+
+    </paper-item>
+  </template>
+  <script>
+    Polymer({
+      is: "config-file-card",
+
+      properties: {
+        name: {
+          type: String
+        },
+
+        link: {
+          type: String
+        }
+      },
+
+      _handleClick: function(event) {
+        window.location = this.link;
+      },
+
+    });
+  </script>
+</dom-module>