size_t on GCC 4.6 and talk/base/rollingaccumulator.h

It looks like including STL headers on GCC 4.6 does not pull stddefs.h any 
longer, so things like size_t are not recognized (unless you use std::size_t). 
That was causing me trouble when trying to compile libjingle on GCC 4.6 due to

http://code.google.com/p/libjingle/source/browse/trunk/talk/base/rollingaccumula
tor.h?spec=svn96&r=96#44

Would it hurt to either include <cstddef> or use std::size_t? I think it 
wouldn't even break the compilation on GCC 4.5.

Please provide any additional information below.
Found this info on 
http://lists.fedoraproject.org/pipermail/devel/2011-February/148523.html

Original issue reported on code.google.com by david.e....@gmail.com on 16 Feb 2012 at 10:28

cookyshi / libjingle

size_t on GCC 4.6 and talk/base/rollingaccumulator.h #303