Don't try to use ManagePasswordsBubbleModel if the password bubble was closed.

chrome/browser/ui/cocoa/passwords/base_passwords_controller_test.mm

 // 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/ui/cocoa/passwords/base_passwords_controller_test.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/password_manager/password_store_factory.h"
 #include "chrome/browser/ui/passwords/manage_passwords_ui_controller_mock.h"
 #include "components/password_manager/core/browser/mock_password_store.h"
@@ skipping 92 matching lines @@
   ASSERT_TRUE(testing::Mock::VerifyAndClearExpectations(ui_controller_));
 }
 
 ManagePasswordsBubbleModel::DisplayReason
 ManagePasswordsControllerTest::GetDisplayReason() const {
   return ManagePasswordsBubbleModel::AUTOMATIC;
 }
 
 @implementation ContentViewDelegateMock
 
+@synthesize model = _model;
 @synthesize dismissed = _dismissed;
 
 - (void)viewShouldDismiss {
   _dismissed = YES;
 }
 
 @end