This is a reland of ec952aaa.

Included is a fix that ensures that top_on_previous_step_ is cleared when we
release a page.

Original change's description:
> Reland "[profiler] proper observation of old space inline allocations"
>
> This is a reland of 672a41c3
> Original change's description:
> > [profiler] proper observation of old space inline allocations
> >
> > Bug: chromium:633920
> > Change-Id: I9a2f4a89f6b9c0f63cb3b166b06a88a12f0a203c
> > Reviewed-on: https://chromium-review.googlesource.com/631696
> > Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#48043}
>
> Bug: chromium:633920
> Change-Id: I6fe743d31b8ff26f3858488d4c014c62d3c85add
> Reviewed-on: https://chromium-review.googlesource.com/671127
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
> Cr-Commit-Position: refs/heads/master@{#48085}

Bug: chromium:633920
Change-Id: I8a0dcc4eaffc1f1d3ac5b3f8d344001cdae36606
Reviewed-on: https://chromium-review.googlesource.com/677407Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ali Ijaz Sheikh <ofrobots@google.com>
Cr-Commit-Position: refs/heads/master@{#48141}