Refactor ProgramBinary entry points. These will need to set dirty bits for the program, and this is best done via the Context. BUG=angleproject:747 Change-Id: I1379d2d4be0e94206c0aa7cb1546aa1a591f23ff Reviewed-on: https://chromium-review.googlesource.com/529767 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>