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

ash/keyboard_overlay/keyboard_overlay_view.h

Index: ash/keyboard_overlay/keyboard_overlay_view.h
diff --git a/ash/keyboard_overlay/keyboard_overlay_view.h b/ash/keyboard_overlay/keyboard_overlay_view.h
index 0409d8b967f3a6eaee449e7ac9a73dc1f0ca9128..d83cb13309078818c6dfc7269b70db42f8a07f30 100644
--- a/ash/keyboard_overlay/keyboard_overlay_view.h
+++ b/ash/keyboard_overlay/keyboard_overlay_view.h
@@ -20,6 +20,8 @@ namespace ui {
 class WebDialogDelegate;
 }
 
+namespace ash {
+
 // A customized dialog view for the keyboard overlay.
 class ASH_EXPORT KeyboardOverlayView
     : public views::WebDialogView,
@@ -47,4 +49,6 @@ class ASH_EXPORT KeyboardOverlayView
   DISALLOW_COPY_AND_ASSIGN(KeyboardOverlayView);
 };
 
+}  // namespace ash
+
 #endif  // ASH_KEYBOARD_OVERLAY_KEYBOARD_OVERLAY_VIEW_H_