add flag for google3

BUG=skia:6366

Change-Id: If87770912c0f88816db0586bf7013b7e5788fcef
NOTRY=True
Reviewed-on: https://skia-review.googlesource.com/9861
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed