The HeapController is now refactored in a way that new controllers only
need to specify the constants that define how a space grows and shrinks.

Bug: chromium:845409
Change-Id: I804eed440a791d6fbd232b7540a1cbe66b16a5f1
Reviewed-on: https://chromium-review.googlesource.com/1165347
Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55006}