Reland Change minimum length of Aura overlay scrollbars.

ui/native_theme/native_theme_aura.cc

Index: ui/native_theme/native_theme_aura.cc
diff --git a/ui/native_theme/native_theme_aura.cc b/ui/native_theme/native_theme_aura.cc
index 76283878e06a13f8cb77b8adbc90799dfea2aa28..508bfbb223bd1948901272d607204107d0902ab3 100644
--- a/ui/native_theme/native_theme_aura.cc
+++ b/ui/native_theme/native_theme_aura.cc
@@ -33,7 +33,7 @@ namespace {
 // Constants for painting overlay scrollbars. Other properties needed outside
 // this painting code are defined in overlay_scrollbar_constants_aura.h.
 constexpr int kOverlayScrollbarStrokeWidth = 1;
-constexpr int kOverlayScrollbarMinimumLength = 12;
+constexpr int kOverlayScrollbarMinimumLength = 32;
 
 // 2 pixel border with 1 pixel center patch. The border is 2 pixels despite the
 // stroke width being 1 so that the inner pixel can match the center tile