[mus+ash] Removes WmWindow from screen_dimmer and video_detector

ash/wm/screen_dimmer.cc

 // Copyright (c) 2012 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/wm/screen_dimmer.h"
 
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/shell.h"
 #include "ash/window_user_data.h"
 #include "ash/wm/container_finder.h"
@@ skipping 35 matching lines @@
   Update(should_dim);
 }
 
 aura::Window::Windows ScreenDimmer::GetAllContainers() {
   return container_ == Container::ROOT
              ? Shell::GetAllRootWindows()
              : wm::GetContainersFromAllRootWindows(
                    ash::kShellWindowId_LockScreenContainersContainer);
 }
 
-void ScreenDimmer::OnRootWindowAdded(WmWindow* root_window) {
+void ScreenDimmer::OnRootWindowAdded(aura::Window* root_window) {
   Update(is_dimming_);
 }
 
 void ScreenDimmer::Update(bool should_dim) {
   for (aura::Window* container : GetAllContainers()) {
     WindowDimmer* window_dimmer = window_dimmers_->Get(container);
     if (should_dim) {
       if (!window_dimmer) {
         window_dimmers_->Set(container,
                              base::MakeUnique<WindowDimmer>(container));
         window_dimmer = window_dimmers_->Get(container);
         window_dimmer->SetDimOpacity(container_ == Container::ROOT
                                          ? kDimmingLayerOpacityForRoot
                                          : kDimmingLayerOpacityForLockScreen);
       }
       if (at_bottom_)
         container->StackChildAtBottom(window_dimmer->window());
       else
         container->StackChildAtTop(window_dimmer->window());
       window_dimmer->window()->Show();
     } else if (window_dimmer) {
       window_dimmers_->Set(container, nullptr);
     }
   }
 }
 
 }  // namespace ash