Added basic browser test for window.print() from Chrome apps.

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

Index: chrome/test/data/extensions/platform_apps/print_api/test.js
diff --git a/chrome/test/data/extensions/platform_apps/print_api/test.js b/chrome/test/data/extensions/platform_apps/print_api/test.js
new file mode 100644
index 0000000000000000000000000000000000000000..98f0b3efecc2eba3d310225807e70c9842b39355
--- /dev/null
+++ b/chrome/test/data/extensions/platform_apps/print_api/test.js
@@ -0,0 +1,17 @@
+// Copyright (c) 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.app.runtime.onLaunched.addListener(function() {
+  chrome.test.runTests([
+    function testWindowDotPrintCallWorks() {
+      chrome.app.window.create('test.html', {}, chrome.test.callbackPass(
+          function(appWindow) {
+            appWindow.contentWindow.onload = chrome.test.callbackPass(
+                function() {
+                  appWindow.contentWindow.print();
+                });
+          }));
+    }
+  ]);
+});