fix Screen leak in ash tests

ash/shell.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/shell.h"
 
 #include <algorithm>
 #include <string>
 
 #include "ash/accelerators/focus_manager_factory.h"
@@ skipping 167 matching lines @@
 Shell::Shell(ShellDelegate* delegate)
     : screen_(new ScreenAsh),
       active_root_window_(NULL),
       delegate_(delegate),
 #if defined(OS_CHROMEOS)
       output_configurator_(new chromeos::OutputConfigurator()),
       output_configurator_animation_(
           new internal::OutputConfiguratorAnimation()),
 #endif  // defined(OS_CHROMEOS)
       browser_context_(NULL) {
-  gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, screen_);
-  gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_ALTERNATE, screen_);
+  gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_NATIVE, screen_.get());
+  gfx::Screen::SetScreenInstance(gfx::SCREEN_TYPE_ALTERNATE, screen_.get());
   ui_controls::InstallUIControlsAura(internal::CreateUIControls());
 #if defined(OS_CHROMEOS)
   output_configurator_->AddObserver(output_configurator_animation_.get());
   base::MessagePumpAuraX11::Current()->AddDispatcherForRootWindow(
       output_configurator());
 #endif  // defined(OS_CHROMEOS)
 }
 
 Shell::~Shell() {
   views::FocusManagerFactory::Install(NULL);
@@ skipping 548 matching lines @@
        iter != controllers.end(); ++iter) {
     if ((*iter)->GetSystemModalLayoutManager(window)->
             CanWindowReceiveEvents(window)) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace ash