Revert of [heap] Refactor evacuation for young and old gen into visitors. (patchset #5 id:80001 of https://codereview.chromium.org/1470253002/ )

Reason for revert:
Still investigating bad canary.

Original issue's description:
> [heap] Refactor evacuation for young and old gen into visitors.
>
> Create a visitor for evacuating objects for young and old generation. This is
> the first step of preparing a task to process, both,  newspace and oldspace
> pages in parallel.
>
> BUG=chromium:524425
> LOG=N
>
> Committed: https://crrev.com/138d9bae5d7014e0d205634a49b5eac3697744c8
> Cr-Commit-Position: refs/heads/master@{#32349}

TBR=mlippautz@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:524425

Review URL: https://codereview.chromium.org/1483393002

Cr-Commit-Position: refs/heads/master@{#32462}