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

ash/display/multi_display_manager.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/display/multi_display_manager.h"
 
 #include <string>
 #include <vector>
 
 #include "ash/display/display_controller.h"
@@ skipping 176 matching lines @@
     new_displays = updated_displays;
   }
 
   std::sort(displays_.begin(), displays_.end(), DisplaySortFunctor());
   std::sort(new_displays.begin(), new_displays.end(), DisplaySortFunctor());
   DisplayList removed_displays;
   std::vector<size_t> changed_display_indices;
   std::vector<size_t> added_display_indices;
   gfx::Display current_primary;
   if (Shell::HasInstance())
-    current_primary = gfx::Screen::GetPrimaryDisplay();
+    current_primary = Shell::GetAshScreen()->GetPrimaryDisplay();
 
   for (DisplayList::iterator curr_iter = displays_.begin(),
        new_iter = new_displays.begin();
        curr_iter != displays_.end() || new_iter != new_displays.end();) {
     if (curr_iter == displays_.end()) {
       // more displays in new list.
       added_display_indices.push_back(new_iter - new_displays.begin());
       ++new_iter;
     } else if (new_iter == new_displays.end()) {
       // more displays in current list.
@@ skipping 244 matching lines @@
   DisplayList::iterator iter_to_update = to_update->begin();
   DisplayList::const_iterator iter = displays_.begin();
   for (; iter != displays_.end() && iter_to_update != to_update->end();
        ++iter, ++iter_to_update) {
     (*iter_to_update).set_id((*iter).id());
   }
 }
 
 }  // namespace internal
 }  // namespace ash