Version 3.27.17.1 (merged r21597)

Update gn config after r21578

R=mvstanton@chromium.org
BUG=

Review URL: https://codereview.chromium.org/310483006

git-svn-id: https://v8.googlecode.com/svn/trunk@21598 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/trunk' into trunk