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

ash/display/display_controller.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/display_controller.h"
 
 #include <algorithm>
 
 #include "ash/ash_switches.h"
 #include "ash/display/multi_display_manager.h"
@@ skipping 473 matching lines @@
   static bool force_constrain_pointer_to_root =
       CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kAshConstrainPointerToRoot);
   if (base::chromeos::IsRunningOnChromeOS() || force_constrain_pointer_to_root)
     root->ConfineCursorToWindow();
 #endif
   return root;
 }
 
 void DisplayController::UpdateDisplayBoundsForLayout() {
-  if (gfx::Screen::GetNumDisplays() <= 1)
+  if (Shell::GetAshScreen()->GetNumDisplays() <= 1)
     return;
 
-  DCHECK_EQ(2, gfx::Screen::GetNumDisplays());
+  DCHECK_EQ(2, Shell::GetAshScreen()->GetNumDisplays());
   const gfx::Rect& primary_bounds = GetPrimaryDisplay().bounds();
 
   gfx::Display* secondary_display = GetSecondaryDisplay();
   const gfx::Rect& secondary_bounds = secondary_display->bounds();
   gfx::Point new_secondary_origin = primary_bounds.origin();
 
   const DisplayLayout& layout = GetLayoutForDisplay(*secondary_display);
   DisplayLayout::Position position = layout.position;
 
   // Ignore the offset in case the secondary display doesn't share edges with
@@ skipping 28 matching lines @@
   secondary_display->set_bounds(
       gfx::Rect(new_secondary_origin, secondary_bounds.size()));
   secondary_display->UpdateWorkAreaFromInsets(insets);
 }
 
 void DisplayController::NotifyDisplayConfigurationChanging() {
   FOR_EACH_OBSERVER(Observer, observers_, OnDisplayConfigurationChanging());
 }
 
 }  // namespace ash