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

ash/wm/shelf_layout_manager.cc

Index: ash/wm/shelf_layout_manager.cc
diff --git a/ash/wm/shelf_layout_manager.cc b/ash/wm/shelf_layout_manager.cc
index 46023ccb3abe65758c96947a0196fc13f4deaae8..af80acb9cb633dcf67f0cdf10a9d80b8fddfa411 100644
--- a/ash/wm/shelf_layout_manager.cc
+++ b/ash/wm/shelf_layout_manager.cc
@@ -879,8 +879,10 @@ ShelfLayoutManager::AutoHideState ShelfLayoutManager::CalculateAutoHideState(
                            -kNotificationBubbleGapHeight : 0,
                        0);
   }
-  return shelf_region.Contains(gfx::Screen::GetCursorScreenPoint()) ?
-      AUTO_HIDE_SHOWN : AUTO_HIDE_HIDDEN;
+  return shelf_region.Contains(
+      ash::Shell::GetAshScreen()->GetCursorScreenPoint()) ?
+          AUTO_HIDE_SHOWN :
+          AUTO_HIDE_HIDDEN;
 }
 
 void ShelfLayoutManager::UpdateHitTestBounds() {