Refactor UniformMatrix validation. Move the shared validation logic to validationES.cpp. BUG=angle:571 Change-Id: I2fb06a012703c647de2176914238b48665145c6f Reviewed-on: https://chromium-review.googlesource.com/200073 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>