Add context to gfx::Screen calls in support of simultaneous desktop+ash

ash/wm/window_util.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/window_util.h"
 
 #include <vector>
 
 #include "ash/shell.h"
 #include "ash/wm/activation_controller.h"
@@ skipping 90 matching lines @@
 }
 
 void ToggleMaximizedWindow(aura::Window* window) {
   if (ash::wm::IsWindowMaximized(window))
     ash::wm::RestoreWindow(window);
   else if (ash::wm::CanMaximizeWindow(window))
     ash::wm::MaximizeWindow(window);
 }
 
 void CenterWindow(aura::Window* window) {
-  const gfx::Display display = gfx::Screen::GetDisplayNearestWindow(window);
+  const gfx::Display display =
+      Shell::GetAshScreen()->GetDisplayNearestWindow(window);
   gfx::Rect center = display.work_area().Center(window->bounds().size());
   window->SetBounds(center);
 }
 
 ui::Layer* RecreateWindowLayers(aura::Window* window, bool set_bounds) {
   const gfx::Rect bounds = window->bounds();
   ui::Layer* old_layer = window->RecreateLayer();
   DCHECK(old_layer);
   for (aura::Window::Windows::const_iterator it = window->children().begin();
        it != window->children().end();
@@ skipping 12 matching lines @@
        it != children.end();
        ++it) {
     ui::Layer* child = *it;
     DeepDeleteLayers(child);
   }
   delete layer;
 }
 
 }  // namespace wm
 }  // namespace ash