heap: Remove infra to track stack frame depth

Oilpan switched to non-eager tracing of objects recently. This removes
the now unused infra to track stack frame depth.

Bug: 933333
Change-Id: I8d75b6219cff838d20c8be5b71d62a85b005e339
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1524491
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641665}
11 files changed