Switch platform apps from a declarative launch container to handling an onLaunched event.

chrome/test/data/extensions/platform_apps/launch/test.js

Index: chrome/test/data/extensions/platform_apps/launch/test.js
diff --git a/chrome/test/data/extensions/platform_apps/launch/test.js b/chrome/test/data/extensions/platform_apps/launch/test.js
new file mode 100644
index 0000000000000000000000000000000000000000..67d10fc5ee728fb8bc7e73aec00682997bab7a98
--- /dev/null
+++ b/chrome/test/data/extensions/platform_apps/launch/test.js
@@ -0,0 +1,7 @@
+// Copyright (c) 2012 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.experimental.runtime.onLaunched.addListener(function() {
+  chrome.test.notifyPass();
+});