Fix flakey test by making sure WebUI dialog is shut down before test completion.

BUG=89931
TEST=Run the test on a loaded single-CPU system before and after the change.
Before, notice the dialog staying up past when the main windows goes away,
won't get through more than 1 or 2 repeats before breaking.
After, dialog goes away first, no more flakey.


Review URL: http://codereview.chromium.org/7747036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98576 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/printing/print_dialog_cloud_uitest.cc

@@ -236,6 +236,13 @@ IN_PROC_BROWSER_TEST_F(PrintDialogCloudTest, HandlersRegistered) {
   ui_test_utils::RunMessageLoop();
 
   ASSERT_TRUE(TestController::GetInstance()->result());
+
+  // Close the dialog before finishing the test.
+  ui_test_utils::WindowedNotificationObserver signal(
+      content::NOTIFICATION_TAB_CLOSED, NotificationService::AllSources());
+  EXPECT_TRUE(ui_test_utils::SendKeyPressSync(browser(), ui::VKEY_ESCAPE,
+                                              false, false, false, false));
+  signal.Wait();
 }
 
 #if defined(OS_CHROMEOS)