98ee14e936
by making sure that other_rewrite_driver gets cleaned up: the test sets RewriteTestBase into managed mode, which basically means it does rewrite_driver = NewRewriteDriver other_rewrite_driver = NewRewriterDriver ... but then nothing actually does anything with other_rewrite_driver, making it stick-around until factory shutdown does emergency cleanup. (see https://github.com/pagespeed/mod_pagespeed/issues/1421)