Fix compilation on mingw BUG=angleproject:1795 Change-Id: Ic25805f99154395c9af28197ceb1218f9c5c3138 Reviewed-on: https://chromium-review.googlesource.com/434457 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>