Reland "benchmark: add basic partition allocator coverage"

This is a reland of 7ff0fd56e408cc7c4c3e353ca84b500e8228e7d6 with a
lower maximum timeout set on the test (the original CL was causing
some perf bots within Google to time out).

Original changes description:
> benchmark: add basic partition allocator coverage
>
> Intention of this benchmark is to collect profiling data of hotspots
> within the partition allocator and a performance baseline for
> work on thread-local caches.
>
> Bug: 907444
> Change-Id: Ia112fad5e23dfdf47f44077ed3ab776b13ddf0b3
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1350878
> Commit-Queue: Richard Townsend <richard.townsend@arm.com>
> Reviewed-by: François Doray <fdoray@chromium.org>
> Reviewed-by: Kentaro Hara <haraken@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#642530}

Bug: 907444
Change-Id: I1e4f8daa1d52052906d22454494a17b8421a91f8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1547794
Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Richard Townsend <richard.townsend@arm.com>
Cr-Commit-Position: refs/heads/master@{#646977}
2 files changed