Version 3.29.88.9 (merged r24361)

Fix data race when concurrent compilation is aborted due to dependency change.

BUG=chromium:419189
LOG=N
R=mvstanton@chromium.org

Review URL: https://codereview.chromium.org/639693006

git-svn-id: https://v8.googlecode.com/svn/branches/3.29@24702 ce2b1a6d-e550-0410-aec6-3dcde31c8c00