Version 3.28.71.15 (merged r23824)

Remove guard page mechanism from promotion queue.

BUG=chromium:411210
LOG=N
TBR=jarin@chromium.org

Review URL: https://codereview.chromium.org/617493005

git-svn-id: https://v8.googlecode.com/svn/branches/3.28@24300 ce2b1a6d-e550-0410-aec6-3dcde31c8c00