Reland Change minimum length of Aura overlay scrollbars.

third_party/WebKit/Source/platform/scroll/ScrollbarThemeOverlay.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 252 matching lines @@
   DCHECK(usesNinePatchThumbResource());
 
   WebThemeEngine::Part part = WebThemeEngine::PartScrollbarHorizontalThumb;
   if (scrollbar.orientation() == VerticalScrollbar)
     part = WebThemeEngine::PartScrollbarVerticalThumb;
 
   DCHECK(Platform::current()->themeEngine());
   return Platform::current()->themeEngine()->ninePatchAperture(part);
 }
 
+int ScrollbarThemeOverlay::minimumThumbLength(
+    const ScrollbarThemeClient& scrollbar) {
+  if (scrollbar.orientation() == VerticalScrollbar) {
+    return Platform::current()
+        ->themeEngine()
+        ->getSize(WebThemeEngine::PartScrollbarVerticalThumb)
+        .height;
+  }
+
+  return Platform::current()
+      ->themeEngine()
+      ->getSize(WebThemeEngine::PartScrollbarHorizontalThumb)
+      .width;
+}
+
 }  // namespace blink