[mus+ash] Removes WmWindow from screen_dimmer and video_detector

ash/root_window_controller.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/root_window_controller.h"
 
 #include <algorithm>
 #include <queue>
 #include <vector>
 
@@ skipping 740 matching lines @@
     if (Shell::GetAshConfig() != Config::MASH)
       shell->InitKeyboard();
   } else {
     window_tree_host_->Show();
 
     // At the login screen the shelf will be hidden because its container window
     // is hidden. InitializeShelf() will make it visible.
     InitializeShelf();
 
     // Notify shell observers about new root window.
-    shell->OnRootWindowAdded(WmWindow::Get(root_window));
+    shell->OnRootWindowAdded(root_window);
   }
 
   // TODO: AshTouchExplorationManager doesn't work with mus.
   // http://crbug.com/679782
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kAshDisableTouchExplorationMode) &&
       Shell::GetAshConfig() != Config::MASH) {
     touch_exploration_manager_.reset(new AshTouchExplorationManager(this));
   }
 }
@@ skipping 308 matching lines @@
     EnableTouchHudProjection();
   else
     DisableTouchHudProjection();
 }
 
 RootWindowController* GetRootWindowController(const aura::Window* root_window) {
   return root_window ? GetRootWindowSettings(root_window)->controller : nullptr;
 }
 
 }  // namespace ash