Add guard to unblock the Chromium roll

TBR=

Change-Id: I87f96fb88479de770490ce4cce6ad840acb90241
Reviewed-on: https://skia-review.googlesource.com/24261
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
1 file changed