Oilpan: Add Destructor to Promptly Free Stack Allocated HeapHashCollections

This CL adds the destructor in order to promptly freed stack-allocated
HeapHashCollections, and also added tests to check it work exactly.

heap_allocator: We needs to check whether the backing collection is
sweep-forbidden when the destructor is called. So, we added this check flag.


Bug: 854480
Change-Id: If9fc8324b839714ae978665b6f7540d7f5ea15e4
Reviewed-on: https://chromium-review.googlesource.com/1123969
Commit-Queue: Haruka Matsumura <harukamt@google.com>
Reviewed-by: Hayato Ito <hayato@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575570}
8 files changed