This reduces the overhead of reporting allocations to v8 to an
acceptable level.

BUG=none
LOG=n
R=dcarney@chromium.org, hpayer@chromium.org

Review URL: https://codereview.chromium.org/310393003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21688 ce2b1a6d-e550-0410-aec6-3dcde31c8c00