Add a chrome://webapks page.

components/webapks_ui/resources/about_webapks.js

+// Copyright (c) 2017 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.
+
+/**
+ * Creates and returns a node (with |text| as content) assigning it the
+ * |className| class.
+ */
+function createTextElementWithClassName(text, className) {
+  var node = document.createElement('span');
+  node.textContent = text;
+  node.className = className;
+  return node;
+}
+
+/**
+ * Callback from the backend with the information of a WebAPK to display.
+ * This will be called once for each WebAPK available on the device and each
+ * one will be appended at the end of the other.
+ */
+function returnWebApksInfo(appName, packageName, shellApkVersion, versionCode) {
+  var webApksList = $('webapks-list');
+
+  webApksList.appendChild(document.createElement("BR"));
+  webApksList.appendChild(document.createElement("BR"));
+  webApksList.appendChild(createTextElementWithClassName(appName, "app-name"));
+
+  webApksList.appendChild(document.createElement("BR"));
+  webApksList.appendChild(createTextElementWithClassName(
+      loadTimeData.getString('packageName'), "app-property-label"));
+  webApksList.appendChild(document.createTextNode(packageName));
+
+  webApksList.appendChild(document.createElement("BR"));
+  webApksList.appendChild(createTextElementWithClassName(
+      loadTimeData.getString('shellApkVersion'), "app-property-label"));
+  webApksList.appendChild(document.createTextNode(shellApkVersion));
+
+  webApksList.appendChild(document.createElement("BR"));
+  webApksList.appendChild(createTextElementWithClassName(
+      loadTimeData.getString('versionCode'), "app-property-label"));
+  webApksList.appendChild(document.createTextNode(versionCode));
+}
+
+/* All the work we do onload. */
+function onLoadWork() {
+  chrome.send('requestWebApksInfo');
+}
+
+document.addEventListener('DOMContentLoaded', onLoadWork);