remove obsolete flags

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4498

Change-Id: I89941135d223a0ca13c705e9bed6231011f86f40
Reviewed-on: https://skia-review.googlesource.com/4498
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
3 files changed