Delete desktop/shell instance correctly when chrome is shutting down

ui/aura/desktop_host_linux.cc

 // Copyright (c) 2011 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 "ui/aura/desktop_host.h"
 
 #include <X11/cursorfont.h>
 #include <X11/Xlib.h>
 
 // Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
@@ skipping 574 matching lines @@
       xevent.xmotion.x_root = point.x();
       xevent.xmotion.y_root = point.y();
     }
     default:
       break;
   }
   XSendEvent(xdisplay_, xwindow_, False, 0, &xevent);
 }
 
 void DesktopHostLinux::WillDestroyCurrentMessageLoop() {
-  desktop_->DeleteInstance();
+  aura::Desktop::DeleteInstance();
 }
 
 bool DesktopHostLinux::IsWindowManagerPresent() {
   // Per ICCCM 2.8, "Manager Selections", window managers should take ownership
   // of WM_Sn selections (where n is a screen number).
   ::Atom wm_s0_atom = XInternAtom(xdisplay_, "WM_S0", False);
   return XGetSelectionOwner(xdisplay_, wm_s0_atom) != None;
 }
 
 }  // namespace
 
 // static
 DesktopHost* DesktopHost::Create(const gfx::Rect& bounds) {
   return new DesktopHostLinux(bounds);
 }
 
 // static
 gfx::Size DesktopHost::GetNativeScreenSize() {
   ::Display* xdisplay = base::MessagePumpX::GetDefaultXDisplay();
   return gfx::Size(DisplayWidth(xdisplay, 0), DisplayHeight(xdisplay, 0));
 }
 
 }  // namespace aura