Refactor MdFocusRing to make it easier to reuse on other controls.

ui/views/examples/button_sticker_sheet.cc

Index: ui/views/examples/button_sticker_sheet.cc
diff --git a/ui/views/examples/button_sticker_sheet.cc b/ui/views/examples/button_sticker_sheet.cc
index dc98a833cd20b66b234147ebee7cada0eebb8cd4..c560ea140061a58d2be484dea181e8ad2a0a49ab 100644
--- a/ui/views/examples/button_sticker_sheet.cc
+++ b/ui/views/examples/button_sticker_sheet.cc
@@ -116,11 +116,6 @@ void ButtonStickerSheet::CreateExampleView(View* container) {
   AddLabelledRowToGridLayout(layout, "Pressed", {primary, secondary});
   MakeButtonsInState(&primary, &secondary, this, Button::STATE_DISABLED);
   AddLabelledRowToGridLayout(layout, "Disabled", {primary, secondary});
-
-  MakeButtonsInState(&primary, &secondary, this, Button::STATE_NORMAL);
-  primary->OnFocus();
-  secondary->OnFocus();
-  AddLabelledRowToGridLayout(layout, "Focused", {primary, secondary});
 }
 
 void ButtonStickerSheet::ButtonPressed(Button* button, const ui::Event& event) {