Add chrome://site-engagement WebUI.

chrome/browser/resources/engagement/site_engagement.js

+// Copyright 2015 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.
+
+define('main', [
+    'mojo/public/js/bindings',

[Sam McNally, 2015/09/08 08:25:47]

Remove.

[calamity, 2015/09/10 06:57:33]

Done.

+    'mojo/public/js/core',

[Sam McNally, 2015/09/08 08:25:47]

Remove.

[calamity, 2015/09/10 06:57:33]

Done.

+    'mojo/public/js/connection',
+    'chrome/browser/ui/webui/engagement/site_engagement.mojom',
+    'content/public/renderer/service_provider',
+], function(bindings, core, connection, browser, serviceProvider) {

[Sam McNally, 2015/09/08 08:25:47]

s/browser/siteEngagementMojom/

[calamity, 2015/09/10 06:57:33]

Done.

+  'use strict';

[Sam McNally, 2015/09/08 08:25:47]

This can go outside.

[calamity, 2015/09/10 06:57:33]

Done.

+
+  return function() {
+    var browserProxy = connection.bindHandleToProxy(

[Sam McNally, 2015/09/08 08:25:47]

How about uiHandler?

[calamity, 2015/09/10 06:57:33]

Done.

+        serviceProvider.connectToService(
+            browser.SiteEngagementUIHandlerMojo.name),
+        browser.SiteEngagementUIHandlerMojo);
+
+    var pipe = core.createMessagePipe();

[Sam McNally, 2015/09/08 08:25:47]

Remove.

[calamity, 2015/09/10 06:57:33]

Done.

+
+    // Populate engagement table.
+    browserProxy.getSiteEngagementInfo().then(function(response) {

[Sam McNally, 2015/09/08 08:25:47]

then(response => {

[calamity, 2015/09/10 06:57:33]

Done.

+      $('engagement-table').engagementInfo = response.info;
+    });
+  };
+});