Re-reland: chromeos: Fix shelf appearing at login screen under mash

chrome/browser/ui/ash/multi_user/multi_user_window_manager_stub.cc

 // Copyright 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.
 
 #include "chrome/browser/ui/ash/multi_user/multi_user_window_manager_stub.h"
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "components/signin/core/account_id/account_id.h"
 
 namespace chrome {
 
+MultiUserWindowManagerStub::MultiUserWindowManagerStub() {}
+
+MultiUserWindowManagerStub::~MultiUserWindowManagerStub() {}
+
 void MultiUserWindowManagerStub::SetWindowOwner(aura::Window* window,
                                                 const AccountId& account_id) {
   NOTIMPLEMENTED();
 }
 
 const AccountId& MultiUserWindowManagerStub::GetWindowOwner(
     aura::Window* window) const {
   return EmptyAccountId();
 }
 
@@ skipping 27 matching lines @@
 
 void MultiUserWindowManagerStub::AddObserver(Observer* observer) {
   NOTIMPLEMENTED();
 }
 
 void MultiUserWindowManagerStub::RemoveObserver(Observer* observer) {
   NOTIMPLEMENTED();
 }
 
 }  // namespace chrome