ConcurrentLinkedHashMap -> Caffeine when Java-8 based

[GoogleCodeExporter]

When transitioning to requiring Java 8, please upgrade to Caffeine [1]. The 
performance should be relatively the same and the per-instance memory usage 
should be smaller.

ConcurrentLinkedHashMap [2] changes will continue to be minimal, even more so 
now, and driven by requests from Java 6 users unable to upgrade. Caffeine is 
ideally the upgrade path for Guava cache users too, which due to Android cannot 
be significantly modified.

[1] https://github.com/ben-manes/caffeine
[2] https://code.google.com/p/concurrentlinkedhashmap

Original issue reported on code.google.com by [email protected] on 11 Apr 2015 at 1:46