Everything was including log.h through heap-inl.h, so remove that
include by moving the one user into heap.cc, and then fix all the
include errors.

This reduces the log.h include ball from ~550 to ~100.

Change-Id: I6d09bc2f365b48645fcfdc695a68ea12539a745d
Reviewed-on: https://chromium-review.googlesource.com/c/1424198
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58981}