This cleans up the allocation and deallocation of Blend, DepthStencil,
Rasterizer, and Sampler states.

This patch introduces a LazyResource2 class, basically a replacement
for LazyResource, which will be removed once the refactor is done.

BUG=angleproject:2034

Change-Id: I4fa759ae479807ff69a629f89a08b01800ba3f66
Reviewed-on: https://chromium-review.googlesource.com/503627
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>