Add browser test cases for tab and audio share, which are new functionality of desktop share.

chrome/test/data/extensions/api_test/desktop_capture/test.js

 // Copyright 2013 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.test.runTests([
   function emptySourceList() {
     chrome.desktopCapture.chooseDesktopMedia(
         [],
         chrome.test.callback(function(id) {
           chrome.test.assertEq("undefined", typeof id);
@@ skipping 63 matching lines @@
         ["screen", "window"], onPickerResult);
   },
 
   function cancelDialog() {
     var requestId = chrome.desktopCapture.chooseDesktopMedia(
         ["screen", "window"],
         chrome.test.fail);
     chrome.test.assertEq("number", typeof requestId);
     chrome.desktopCapture.cancelChooseDesktopMedia(requestId);
     chrome.test.succeed();
+  },
+
+  function tabShare() {
+    chrome.desktopCapture.chooseDesktopMedia(
+        ["screen", "window", "tab"],
+        chrome.test.succeed);
+  },
+
+  function audioShare() {
+    chrome.desktopCapture.chooseDesktopMedia(
+        ["screen", "window", "audio"],
+        chrome.test.succeed);
+  },
+
+  function tabShareWithAudioGetStream() {
+    function onPickerResult(id) {
+      chrome.test.assertEq("string", typeof id);
+      chrome.test.assertTrue(id != "");
+      navigator.webkitGetUserMedia({
+        audio: { mandatory: { chromeMediaSource: "desktop",
+                              chromeMediaSourceId: id } },
+        video: { mandatory: { chromeMediaSource: "desktop",
+                              chromeMediaSourceId: id } }
+      },
+      function(stream) {
+         chrome.test.assertEq(1, stream.getAudioTracks().length);
+         chrome.test.succeed();
+      }, chrome.test.fail);
+    }
+
+    chrome.desktopCapture.chooseDesktopMedia(
+        ["tab", "audio"], onPickerResult);
+  },
+
+  function windowShareWithAudioGetStream() {
+    function onPickerResult(id) {
+      chrome.test.assertEq("string", typeof id);
+      chrome.test.assertTrue(id != "");
+      navigator.webkitGetUserMedia({
+        audio: { mandatory: { chromeMediaSource: "desktop",
+                              chromeMediaSourceId: id } },
+        video: { mandatory: { chromeMediaSource: "desktop",
+                              chromeMediaSourceId: id } }
+      },
+      function(stream) {
+         // For window share, we cannot support audio. This test is to make
+         // sure that our code does not crash.
+         chrome.test.assertEq(0, stream.getAudioTracks().length);
+         chrome.test.succeed();
+      }, chrome.test.fail);
+    }
+
+    chrome.desktopCapture.chooseDesktopMedia(
+        ["window", "audio"], onPickerResult);
   }
 ]);