Provide ability for WebUIBrowserTests to run asynchronous tests.

chrome/test/data/webui/async.js

+// Copyright (c) 2011 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.
+
+/**
+ * Fails always.
+ * @throw {Error}
+ */
+function testFailsAssert() {
+  assertNotReached();
+  chrome.send('testContinues');
+  assertNotReached();
+}
+
+/**
+ * Records failure.
+ */
+function testFailsExpect() {
+  expectNotReached();
+  chrome.send('testContinues');
+  expectNotReached();
+}
+
+/**
+ * Passes and sends asyncTestDone message for browser_test to call
+ * asyncTestDone().
+ */
+function testPasses() {
+  expectTrue(true);
+  chrome.send('testContinues');
+  assertFalse(false);
+}
+
+/**
+ * Wraps the function represented by |name| similar to the way net_internals
+ * tests are wrapped.
+ * @param {string} name The name of the function to run.
+ */
+function runAsync(name) {
+  // Strip |name| from arguments.
+  var testArguments = Array.prototype.slice.call(arguments, 1);
+
+  // call async function.
+  var result = runTestFunction(name, this[name], testArguments);
+
+  // Pass on success; bail on errors.
+  if (result[0])
+    chrome.send('testPasses');
+  else
+    asyncTestDone(result);
+}
+
+/**
+ * Sends a message to handler to start |testName| and returns.
+ * @param {string} testName The name of the test to run.
+ */
+function startAsyncTest(testName) {
+  chrome.send('startAsyncTest', [testName]);
+}