mash: remove more shell/shelf WmWindow usage.

ash/mus/top_level_window_factory.cc

 // Copyright 2017 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/top_level_window_factory.h"
 
 #include "ash/mus/disconnected_app_handler.h"
 #include "ash/mus/frame/detached_title_area_renderer.h"
 #include "ash/mus/non_client_frame_controller.h"
 #include "ash/mus/property_util.h"
@@ skipping 54 matching lines @@
   const int64_t display_id = GetInitialDisplayId(*properties);
   if (display_id != display::kInvalidDisplayId) {
     for (RootWindowController* root_window_controller :
          RootWindowController::root_window_controllers()) {
       if (GetRootWindowSettings(root_window_controller->GetRootWindow())
               ->display_id == display_id) {
         return root_window_controller;
       }
     }
   }
-  return RootWindowController::ForWindow(
-      Shell::GetWmRootWindowForNewWindows()->aura_window());
+  return GetRootWindowController(Shell::GetRootWindowForNewWindows());
 }
 
 // Returns the bounds for the new window.
 gfx::Rect CalculateDefaultBounds(
     WindowManager* window_manager,
     RootWindowController* root_window_controller,
     aura::Window* container_window,
     const std::map<std::string, std::vector<uint8_t>>* properties) {
   gfx::Rect requested_bounds;
   if (GetInitialBounds(*properties, &requested_bounds))
@@ skipping 137 matching lines @@
     if (non_client_frame_controller)
       non_client_frame_controller->set_can_activate(can_focus);
     // No need to persist this value.
     properties->erase(focusable_iter);
   }
   return window;
 }
 
 }  // namespace mus
 }  // namespace ash