Additional warnings found with more testing and added C4267 warning disable only for angle_libpng BUG=angleproject:1120 Change-Id: Ic403dcff5a8018056fa51a8c408e64207f3362eb Reviewed-on: https://chromium-review.googlesource.com/293028Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>
