e638d589fa
When calling operations that create a lot of ProjectControls (e.g. ListProjects) we observe OOMs in our Gerrit jobs from time to time. This commit puts a max. limit on the cache size to prevent this from happening. The approach implemented is not an LRU. On purpose, we want to keep PerThreadCache simple and don't add a dependency on e.g. Guava's LRU. Change-Id: Ic2f6e11719b52ee2112f72698e887cbf8ca254d0