Mac: Delete now-dead elastic overscroll code

Source/config.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2013 Apple Inc.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  * Copyright (C) 2010, 2011 Research In Motion Limited. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 78 matching lines @@
 #define WTF_USE_LOW_QUALITY_IMAGE_INTERPOLATION 1
 #define WTF_USE_LOW_QUALITY_IMAGE_NO_JPEG_DITHERING 1
 #define WTF_USE_LOW_QUALITY_IMAGE_NO_JPEG_FANCY_UPSAMPLING 1
 #else
 #define WTF_USE_ICCJPEG 1
 #define WTF_USE_QCMSLIB 1
 #endif
 
 #if OS(MACOSX)
 #define WTF_USE_CF 1
-#define WTF_USE_RUBBER_BANDING 1
 #endif /* OS(MACOSX) */
 
 #if OS(POSIX)
 #define HAVE_SIGNAL_H 1
 #define HAVE_SYS_TIME_H 1
 #define WTF_USE_PTHREADS 1
 #endif /* OS(POSIX) */
 
 #if !OS(WIN) && !OS(ANDROID)
 #define HAVE_TM_GMTOFF 1
@@ skipping 21 matching lines @@
 #ifdef __cplusplus
 
 // These undefs match up with defines in build/mac/Prefix.h for Mac OS X.
 // Helps us catch if anyone uses new or delete by accident in code and doesn't include "config.h".
 #undef new
 #undef delete
 #include <ciso646>
 #include <cstddef>
 
 #endif