Find display root ServerWindow for located events in mus.

ash/mus/root_window_controller.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/root_window_controller.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <map>
@@ skipping 206 matching lines @@
 
 void RootWindowController::CreateStatusArea() {
   WmWindowMus* status_container =
       GetWindowByShellWindowId(kShellWindowId_StatusContainer);
   // Owned by native widget.
   StatusAreaWidget* status_area_widget =
       new StatusAreaWidget(status_container, wm_shelf_.get());
   status_area_widget->CreateTrayViews();
   // TODO(jamescook): Remove this when ash::StatusAreaLayoutManager and
   // ash::ShelfLayoutManager are working in mash. http://crbug.com/621112
-  status_area_widget->SetBounds(gfx::Rect(845, 720, 120, 40));
+  gfx::Size display_size = display_.bounds().size();
+  status_area_widget->SetBounds(gfx::Rect(display_size.width() - 179,
+                                          display_size.height() - 48, 120, 40));
   if (WmShell::Get()->GetSessionStateDelegate()->IsActiveUserSessionStarted())
     status_area_widget->Show();
 }
 
 }  // namespace mus
 }  // namespace ash