https://crrev.com/c/992236 introduced base::size(), modeled after C++17's std::size() [1]. base::size() contains a constexpr and noexcept overload for plain C arrays, rendering the arraysize() macro obsolete. Since base::size() is more widely applicable, it is the preferred solution and existing usages of arraysize() should be replaced by base:size(array).
[1] http://en.cppreference.com/w/cpp/iterator/size
