Always try to load the extension entry points. Despite many extensions being written against specific versions of the GL spec, some drivers (Intel) expose the extensions in much earlier versions. This leads to issues where the extension string would be present but the entry points were not loaded. BUG=angleproject:1038 Change-Id: Ia87bb3f038f310f6bc3e711a0b2d82717b67ae70 Reviewed-on: https://chromium-review.googlesource.com/286525 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>