Use #include <stdint.h> instead of <cstdint>. This fixes the compile on OSX. BUG=angle:773 Change-Id: I68111e178986bb78b73006a1559ba26120275599 Reviewed-on: https://chromium-review.googlesource.com/238441 Tested-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>