Update Mac memory code references

The Mac malloc interceptor relies on internals of macOS.
Update those internals and links to the 10.15 versions.

This relands 994f22b51a586390c36b5713812baeae1e96262a
with a fix for profiling_client.cc which correctly only
includes a Mac file header on the Mac.

Bug: none
Change-Id: I8132dc1ffeeb0c6b65edb80cc729bcb4836f2121
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2377983
Reviewed-by: Erik Chen <erikchen@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802429}
GitOrigin-RevId: 0b16177e609a6843957391712f3599203dec893f
2 files changed