Fix a GCC warning found by Skia. This only seems to affect GCC's enum-compare warning, because we were comparing an untyped enum with a size_t enum. BUG=None Change-Id: I74b8315cff61344d1b7700b1c56a40d2ffce41e2 Reviewed-on: https://chromium-review.googlesource.com/698296 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>