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',
+    'mojo/public/js/core',
+    'mojo/public/js/connection',
+    'chrome/browser/ui/webui/engagement/site_engagement.mojom',
+    'content/public/renderer/service_provider',
+], function(bindings, core, connection, browser, serviceProvider) {
+  'use strict';
+
+  var page;
+
+  function clearEngagementTable() {
+    var table = $('engagement-table');
+    table.removeChild(table.getElementsByTagName('tbody')[0]);
+    table.appendChild(document.createElement('tbody'));
+  }
+
+  function addEngagementTableRow(origin, score) {

[Sam McNally, 2015/08/26 08:23:21]

It might be worth using polymer data binding and templating instead of this
boilerplate.

[calamity, 2015/09/08 07:30:06]

Done.

+    var tableBody = document.querySelector('#engagement-table > tbody');
+    var row = document.createElement('tr');
+
+    var originCell = document.createElement('td');
+    originCell.textContent = origin;
+    originCell.className = 'origin-cell';
+
+    var scoreCell = document.createElement('td');
+    scoreCell.textContent = score;
+
+    row.appendChild(originCell);
+    row.appendChild(scoreCell);
+    tableBody.appendChild(row);
+  }
+
+  function redrawEngagementTable() {

[Sam McNally, 2015/08/26 08:23:21]

Why not make this a method of SiteEngagementPageImpl?

[calamity, 2015/09/08 07:30:06]

I guess I thought that SiteEngagementPageImpl was for the message-y stuff. Moved
all of the stuff in.

+    clearEngagementTable();
+    for (var i = 0; i < page.info.length; i++) {
+      var site = page.info[i];
+      addEngagementTableRow(site.origin, site.score);
+    }
+  }
+
+  function SiteEngagementPageImpl(browser) {
+    this.browser_ = browser;
+    this.info = [];
+  }
+
+  SiteEngagementPageImpl.prototype =
+      Object.create(browser.SiteEngagementPage.stubClass.prototype);
+
+  SiteEngagementPageImpl.prototype.handleSiteEngagementInfo = function(info) {
+    this.info = info;
+    redrawEngagementTable();
+  };
+
+  return function() {
+    var browserProxy = connection.bindHandleToProxy(
+        serviceProvider.connectToService(
+            browser.SiteEngagementUIHandlerMojo.name),
+        browser.SiteEngagementUIHandlerMojo);
+    page = new SiteEngagementPageImpl(browserProxy);
+
+    var pipe = core.createMessagePipe();
+    var stub =
+        connection.bindHandleToStub(pipe.handle0, browser.SiteEngagementPage);
+    bindings.StubBindings(stub).delegate = page;
+    page.stub_ = stub;
+
+    // Populate engagement table.
+    page.browser_.getSiteEngagementInfo(pipe.handle1);
+  };
+});