It's surprising and unexpected that MultiThreadedCertVerifier is also responsible for managing the cache of certificate verification results.
To make it easier to experiment with different caching strategies, including cache persistence, split the cache management out of MultiThreadedCertVerifier, so that the MultiThreadedCertVerifier is only responsible for handling the threading/management aspect, and a CachingCertVerifier can impose memoizaton upon it.
Comment 1 by bugdroid1@chromium.org
, May 20 2016