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

ash/keyboard_overlay/keyboard_overlay_delegate.h

Index: ash/keyboard_overlay/keyboard_overlay_delegate.h
diff --git a/ash/keyboard_overlay/keyboard_overlay_delegate.h b/ash/keyboard_overlay/keyboard_overlay_delegate.h
index 7a63ee5cea0f76d468a0207909579c9d27bbbd53..48101e03b29f1625e8d93d6dc0b18a146097732e 100644
--- a/ash/keyboard_overlay/keyboard_overlay_delegate.h
+++ b/ash/keyboard_overlay/keyboard_overlay_delegate.h
@@ -14,6 +14,8 @@ namespace views {
 class WebDialogView;
 }
 
+namespace ash {
+
 class KeyboardOverlayDelegate : public ui::WebDialogDelegate {
  public:
   KeyboardOverlayDelegate(const string16& title, const GURL& url);
@@ -53,4 +55,6 @@ class KeyboardOverlayDelegate : public ui::WebDialogDelegate {
   DISALLOW_COPY_AND_ASSIGN(KeyboardOverlayDelegate);
 };
 
+}  // namespace ash
+
 #endif  // ASH_KEYBOARD_OVERLAY_KEYBOARD_OVERLAY_DELEGATE_H_