Wait for OobeWebUI to finish loading before running tests.

chrome/browser/chromeos/login/test/oobe_base_test.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 "chrome/browser/chromeos/login/test/oobe_base_test.h"
 
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
+#include "base/run_loop.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager.h"
 #include "chrome/browser/chromeos/login/session/user_session_manager_test_api.h"
 #include "chrome/browser/chromeos/login/test/https_forwarder.h"
 #include "chrome/browser/chromeos/login/ui/webui_login_view.h"
 #include "chrome/browser/chromeos/net/network_portal_detector_test_impl.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/ui/webui/signin/get_auth_frame.h"
 #include "chrome/common/chrome_paths.h"
@@ skipping 84 matching lines @@
 
   js_checker_.set_web_contents(
       LoginDisplayHost::default_host()->GetWebUILoginView()->GetWebContents());
 
   test::UserSessionManagerTestApi session_manager_test_api(
       UserSessionManager::GetInstance());
   session_manager_test_api.SetShouldObtainTokenHandleInTests(false);
 
   LoginDisplayHostImpl::DisableRestrictiveProxyCheckForTest();
 
+  // Wait for OobeUI to finish loading.
+  base::RunLoop run_loop;
+  if (!LoginDisplayHost::default_host()->GetOobeUI()->IsJSReady(
+          run_loop.QuitClosure())) {
+    run_loop.Run();
+  }
+
   ExtensionApiTest::SetUpOnMainThread();
 }
 
 void OobeBaseTest::TearDownOnMainThread() {
   // If the login display is still showing, exit gracefully.
   if (LoginDisplayHost::default_host()) {
     base::MessageLoop::current()->PostTask(FROM_HERE,
                                            base::Bind(&chrome::AttemptExit));
     content::RunMessageLoop();
   }
@@ skipping 133 matching lines @@
       "document.getElementById('$FieldId').value = '$FieldValue';"
       "var e = new Event('input');"
       "document.getElementById('$FieldId').dispatchEvent(e);"
       "})();";
   base::ReplaceSubstringsAfterOffset(&js, 0, "$FieldId", field_id);
   base::ReplaceSubstringsAfterOffset(&js, 0, "$FieldValue", field_value);
   ExecuteJsInSigninFrame(js);
 }
 
 }  // namespace chromeos