views/mus: Have explicit ownership of views::WindowManagerConnection.

mash/screenlock/screenlock.cc

 // Copyright 2016 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 "mash/screenlock/screenlock.h"
 
 #include "ash/public/interfaces/container.mojom.h"
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/mus/public/cpp/property_type_converters.h"
@@ skipping 68 matching lines @@
                             const shell::Identity& identity,
                             uint32_t id) {
   tracing_.Initialize(connector, identity.name());
 
   mash::session::mojom::SessionPtr session;
   connector->ConnectToInterface("mojo:mash_session", &session);
   session->AddScreenlockStateListener(
       bindings_.CreateInterfacePtrAndBind(this));
 
   aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
-  views::WindowManagerConnection::Create(connector, identity);
+  window_manager_connection_ =
+      views::WindowManagerConnection::Create(connector, identity);
 
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.delegate = new ScreenlockView(connector);
 
   std::map<std::string, std::vector<uint8_t>> properties;
   properties[ash::mojom::kWindowContainer_Property] =
       mojo::ConvertTo<std::vector<uint8_t>>(
           static_cast<int32_t>(ash::mojom::Container::LOGIN_WINDOWS));
   mus::Window* window =
       views::WindowManagerConnection::Get()->NewWindow(properties);
   params.native_widget = new views::NativeWidgetMus(
       widget, connector, window, mus::mojom::SurfaceType::DEFAULT);
   widget->Init(params);
   widget->Show();
 }
 
 void Screenlock::ScreenlockStateChanged(bool screen_locked) {
   if (!screen_locked)
     base::MessageLoop::current()->QuitWhenIdle();
 }
 
 }  // namespace screenlock
 }  // namespace mash