Move old-space allocation tracking into Heap::AllocateRaw.

R=yurys@chromium.org

Review URL: https://codereview.chromium.org/68663002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17625 ce2b1a6d-e550-0410-aec6-3dcde31c8c00