Improve appearance of focus rings at fractional scales.

ui/views/painter.h

Index: ui/views/painter.h
diff --git a/ui/views/painter.h b/ui/views/painter.h
index a018e04039ca8225ca0b90683cea4de70a350fb9..5757336387cfb01d718f2633bbbd06732aa79cdf 100644
--- a/ui/views/painter.h
+++ b/ui/views/painter.h
@@ -87,9 +87,10 @@ class VIEWS_EXPORT Painter {
   static std::unique_ptr<Painter> CreateSolidFocusPainter(
       SkColor color,
       const gfx::Insets& insets);
+  // |thickness| is in dip.
   static std::unique_ptr<Painter> CreateSolidFocusPainter(
       SkColor color,
-      SkScalar thickness,
+      int thickness,
       const gfx::InsetsF& insets);
 
   // Returns the minimum size this painter can paint without obvious graphical