Use HashingMRUCache in InputLayoutCache. This simplifies the state management code inside this manager. Also it should improve the speed of lookups due to using hashing instead of a tree lookup. BUG=angleproject:1156 BUG=angleproject:2044 Change-Id: I19ea8dbac6f2dfd7d30dd403d77b66ba0aa85d73 Reviewed-on: https://chromium-review.googlesource.com/527693 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>