bluetooth: Add device list retrieval for chrome://bluetooth-internals

chrome/browser/resources/bluetooth_internals/bluetooth_internals.js

 // Copyright 2016 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.
 
 /**
  * Javascript for bluetooth_internals.html, served from
  *     chrome://bluetooth-internals/.
  */
 
-document.addEventListener('DOMContentLoaded', function() {
-  console.log('Welcome to Bluetooth Internals.');
-});
+/**
+ * The implementation of AdapterClient in
+ *     device/bluetooth/public/interfaces/adapter.mojom.
+ */
+class AdapterClient {
+  /**
+   * Prints added device to console.
+   * @param {!Object} device the device that was added
+   */
+  deviceAdded(device) {
+    console.log('Device added');
+    console.log(device);
+  }
+
+  /**
+   * Prints removed device to console.
+   * @param {!Object} device the device that was removed
+   */
+  deviceRemoved(device) {
+    console.log('Device removed');
+    console.log(device);
+  }
+};
+
+(function() {
+  let adapter = null;
+  let adapterClient = null;
+  let adapterClientHandle = null;
+
+  /**
+   * Helper to convert callback-based define() API to a promise-based API.
+   * @param {!Array<string>} moduleNames
+   * @return {!Promise}
+   */
+  function importModules(moduleNames) {
+    return new Promise(function(resolve, reject) {
+      define(moduleNames, function(var_args) {
+        resolve(Array.prototype.slice.call(arguments, 0));
+      });
+    });
+  }
+
+  /**
+   * Initializes Mojo proxies for page and Bluetooth services.
+   * @return {!Promise}
+   */
+  function initializeProxies() {
+    return importModules([
+             'content/public/renderer/frame_interfaces',
+             'device/bluetooth/public/interfaces/adapter.mojom',
+             'mojo/public/js/connection',
+           ])
+        .then(([frameInterfaces, bluetoothAdapter, connection]) => {
+          console.log('Loaded modules');
+
+          // Hook up the instance properties
+          Object.setPrototypeOf(
+              AdapterClient.prototype,
+              bluetoothAdapter.AdapterClient.stubClass.prototype);
+
+
+          // Create a message pipe and bind one end to client
+          // implementation
+          adapterClient = new AdapterClient();
+          adapterClientHandle = connection.bindStubDerivedImpl(adapterClient);
+
+          adapter = connection.bindHandleToProxy(
+              frameInterfaces.getInterface(bluetoothAdapter.Adapter.name),
+              bluetoothAdapter.Adapter);
+
+          adapter.setClient(adapterClientHandle);
+        });
+  }
+
+  document.addEventListener('DOMContentLoaded', function() {
+    initializeProxies()
+        .then(() => adapter.getDevices())
+        .then(response => console.log(response.devices));
+  });
+})();