Add the first app_shell_browsertest test.

apps/shell/browser/shell_browsertest.cc

+// Copyright 2014 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.
+
+#include "apps/shell/test/app_shell_test.h"
+
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/path_service.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/test/test_utils.h"
+#include "extensions/common/extension_paths.h"
+
+namespace apps {
+
+IN_PROC_BROWSER_TEST_F(AppShellTest, Basic) {

[James Cook, 2014/04/08 16:03:49]

Please comment what the test is testing.

+  base::FilePath test_data_dir;
+
+  content::WindowedNotificationObserver test_pass_observer(
+      chrome::NOTIFICATION_EXTENSION_TEST_PASSED,
+      content::NotificationService::AllSources());
+
+  PathService::Get(extensions::DIR_TEST_DATA, &test_data_dir);
+  test_data_dir = test_data_dir.AppendASCII("platform_app");
+  LOG(INFO) << "Loading path: " << test_data_dir.value();

[James Cook, 2014/04/08 16:03:49]

Delete this line?  I don't think we like adding logging in tests.

[Yoyo Zhou, 2014/04/08 21:55:21]

Done.

+  LoadAndLaunchApp(test_data_dir);
+
+  test_pass_observer.Wait();
+}
+
+}  // namespace apps