Fix Debian9-Clang build

TBR=bsalomon@google.com
Change-Id: I2e86aa0381d409f1205bdaba4117253cb381b404
Reviewed-on: https://skia-review.googlesource.com/65020
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
1 file changed