Refactor ViewsDelegate and MD-ify the icon-to-text spacing for checkbox and radiobutton

ui/views/bubble/bubble_frame_view.cc

Index: ui/views/bubble/bubble_frame_view.cc
diff --git a/ui/views/bubble/bubble_frame_view.cc b/ui/views/bubble/bubble_frame_view.cc
index 14f5622aba174aeff0115960fd7b8cb22cf925a6..a8220bc7a0771f400516dfc07091f7e35abf86ca 100644
--- a/ui/views/bubble/bubble_frame_view.cc
+++ b/ui/views/bubble/bubble_frame_view.cc
@@ -314,8 +314,8 @@ void BubbleFrameView::Layout() {
     return;
 
   // The close button is positioned somewhat closer to the edge of the bubble.
-  const int close_margin =
-      ViewsDelegate::GetInstance()->GetDialogCloseButtonMargin();
+  const int close_margin = ViewsDelegate::GetInstance()->GetDistanceMetric(
+      DistanceMetric::CLOSE_BUTTON_MARGIN);
   close_->SetPosition(
       gfx::Point(contents_bounds.right() - close_margin - close_->width(),
                  contents_bounds.y() + close_margin));