Refactor audio API tests

extensions/test/data/api_test/audio/add_nodes/background.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.
 
-chrome.audio.OnDevicesChanged.addListener(function (devices) {
-  if (devices.length === 3) {
-    if (devices[0].id != "30001" ||
-        devices[0].stableDeviceId != "80001" ||
-        devices[0].isInput != false ||
-        devices[0].deviceType != "USB" ||
-        devices[0].deviceName != "Jabra Speaker" ||
-        devices[0].displayName != "Jabra Speaker 1") {
-      console.error("Got wrong device property for device:" +
-          JSON.stringify(devices[0]));
-      chrome.test.sendMessage("failure");
-    }
-    if (devices[1].id != "30002" ||
-        devices[1].stableDeviceId != "80002" ||
-        devices[1].isInput != false ||
-        devices[1].deviceType != "USB" ||
-        devices[1].deviceName != "Jabra Speaker" ||
-        devices[1].displayName != "Jabra Speaker 2") {
-      console.error("Got wrong device property for device:" +
-          JSON.stringify(devices[1]));
-      chrome.test.sendMessage("failure");
-    }
-    if (devices[2].id != "30003" ||
-        devices[2].stableDeviceId != "80003" ||
-        devices[2].isInput != false ||
-        devices[2].deviceType != "HDMI" ||
-        devices[2].deviceName != "HDMI output" ||
-        devices[2].displayName != "HDA Intel MID") {
-      console.error("Got wrong device property for device:" +
-          JSON.stringify(devices[2]));
-      chrome.test.sendMessage("failure");
-    }
-    chrome.test.sendMessage("success");
-  } else {
-    console.error("Got unexpected OnNodesChanged event failed");
-    chrome.test.sendMessage("failure");
+chrome.test.runTests([
+  function waitForDeviceChangedEventTests() {
+    chrome.test.listenOnce(chrome.audio.OnDevicesChanged, function(devices) {
+      var deviceList = devices.map(function(device) {
+        return {
+          id: device.id,
+          stableDeviceId: device.stableDeviceId,
+          isInput: device.isInput,
+          deviceType: device.deviceType,
+          deviceName: device.deviceName,
+          displayName: device.displayName
+        };
+      }).sort(function(lhs, rhs) {
+        return Number.parseInt(lhs.id) - Number.parseInt(rhs.id);
+      });
+
+     chrome.test.assertEq([{
+        id: '30001',
+        stableDeviceId: '80001',
+        isInput: false,
+        deviceType: 'USB',
+        deviceName: 'Jabra Speaker',
+        displayName: 'Jabra Speaker 1'
+      }, {
+        id: '30002',
+        stableDeviceId: '80002',
+        isInput: false,
+        deviceType: 'USB',
+        deviceName: 'Jabra Speaker',
+        displayName: 'Jabra Speaker 2'
+      }, {
+        id: '30003',
+        stableDeviceId: '80003',
+        isInput: false,
+        deviceType: 'HDMI',
+        deviceName: 'HDMI output',
+        displayName: 'HDA Intel MID'
+      }], deviceList);
+    });
   }
-});
-chrome.test.sendMessage("loaded");
+]);
+
+chrome.test.sendMessage('loaded');