Improving the appearance of overlay scrollbars

ui/views/controls/scrollbar/base_scroll_bar.h

Index: ui/views/controls/scrollbar/base_scroll_bar.h
diff --git a/ui/views/controls/scrollbar/base_scroll_bar.h b/ui/views/controls/scrollbar/base_scroll_bar.h
index 9355e7cd87a0e1a96496360cdb486153ba2d463a..5d077737cfa7ad618f391279f2b232fcb8a1009b 100644
--- a/ui/views/controls/scrollbar/base_scroll_bar.h
+++ b/ui/views/controls/scrollbar/base_scroll_bar.h
@@ -78,8 +78,9 @@ class VIEWS_EXPORT BaseScrollBar : public ScrollBar,
   void Update(int viewport_size,
               int content_size,
               int contents_scroll_offset) override;
-  int GetLayoutSize() const override = 0;
   int GetPosition() const override;
+  int GetThickness() const override = 0;
+  bool OverlapsContent() const override;
 
   // ScrollDelegate overrides:
   bool OnScroll(float dx, float dy) override;