bug 1153260 - Remove/reduce test fixtures
bug 1153260 - Remove/reduce test fixtures

Switched simple_page to sample_page, and reduced usage to places that
actually use it. Simplified the sample table, and dropped references to
instances that are no longer used.

mdn/browsercompat,renoirb/browsercompat,jwhitlock/web-platform-compat,mdn/browsercompat,mdn/browsercompat,jwhitlock/web-platform-compat,renoirb/browsercompat,renoirb/browsercompat,jwhitlock/web-platform-compat