This was missing in CppHeap which means the used_bytes counter in
EmbedderTracing was reset to 0 after every GC.

Bug: chromium:1056170
Change-Id: Iddb0aa1eff9cc354622653376c6623364e015c5d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2732668
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73167}