Fix to allow the proxy authentication dialog to appear when hosting gaia in webview.

chrome/browser/chromeos/login/proxy_auth_dialog_browsertest.cc

 // Copyright 2015 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 "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/login_manager_test.h"
@@ skipping 108 matching lines @@
     ASSERT_TRUE(content::ExecuteScript(oobe_ui->web_ui()->GetWebContents(),
                                        "window.domAutomationController.send(!!("
                                        "$('add-user-button').click()"
                                        "));"));
     screen_waiter.Wait();
     auth_dialog_waiter.Wait();
     ASSERT_TRUE(auth_dialog_waiter.login_handler());
   }
 }
 
-// TODO(paulmeyer): Re-enable webview version of this test
-// (once http://crbug.com/452452 is fixed.
 INSTANTIATE_TEST_CASE_P(ProxyAuthOnUserBoardScreenTestSuite,
                         ProxyAuthOnUserBoardScreenTest,
-                        testing::Values(false));
+                        testing::Bool());
 
 }  // namespace chromeos