Revert of Finish eliminating PlatformWindowMus

ash/mus/sysui_application.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 "ash/mus/sysui_application.h"
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 83 matching lines @@
     return mash::wm::mojom::AshWindowType::STATUS_AREA;
   return mash::wm::mojom::AshWindowType::COUNT;
 }
 
 // Creates a StubWindow, which means this window never receives any input event,
 // or displays anything to the user.
 class AshWindowTreeHostMus : public AshWindowTreeHostPlatform {
  public:
   explicit AshWindowTreeHostMus(const gfx::Rect& initial_bounds)
       : AshWindowTreeHostPlatform() {
-    std::unique_ptr<ui::PlatformWindow> window(
-        new ui::StubWindow(this, gfx::kNullAcceleratedWidget));
+    std::unique_ptr<ui::PlatformWindow> window(new ui::StubWindow(this));
     window->SetBounds(initial_bounds);
     SetPlatformWindow(std::move(window));
   }
 
   ~AshWindowTreeHostMus() override {}
 
   void OnBoundsChanged(const gfx::Rect& bounds) override {
     if (platform_window())
       AshWindowTreeHostPlatform::OnBoundsChanged(bounds);
   }
@@ skipping 211 matching lines @@
 void SysUIApplication::Create(
     ::shell::Connection* connection,
     mojo::InterfaceRequest<mash::shelf::mojom::ShelfController> request) {
   mash::shelf::mojom::ShelfController* shelf_controller =
       static_cast<ShelfDelegateMus*>(Shell::GetInstance()->GetShelfDelegate());
   shelf_controller_bindings_.AddBinding(shelf_controller, std::move(request));
 }
 
 }  // namespace sysui
 }  // namespace ash