Fix build (forgot to update BUILD.gn)

TBR=yangguo@chromium.org

Review URL: https://codereview.chromium.org/341063008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22100 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/bleeding_edge' into bleeding_edge