Move eglCreateContext validation into validationEGL. BUG=angle:658 Change-Id: Ibdf601725536edf40c0499aba0402fb160b2c841 Reviewed-on: https://chromium-review.googlesource.com/242035 Reviewed-by: Brandon Jones <bajones@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>