Revert of Replace pinch scrollbars with regular scrollbars.

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 152 matching lines @@
 }
 
 ScrollbarPart ScrollbarThemeOverlay::hitTest(ScrollbarThemeClient* scrollbar, const IntPoint& position)
 {
     if (m_allowHitTest == DisallowHitTest)
         return NoPart;
 
     return ScrollbarTheme::hitTest(scrollbar, position);
 }
 
-ScrollbarTheme* ScrollbarThemeOverlay::mobileTheme()
-{
-    DEFINE_STATIC_LOCAL(ScrollbarThemeOverlay, theme, (3, 3, ScrollbarThemeOverlay::DisallowHitTest, Color(128, 128, 128, 128)));
-    return &theme;
-}
-
 } // namespace blink