Revert of Let GC select the collector when the external memory allocation limit is reached (patchset #1 id:1 of https://codereview.chromium.org/1201993002/)

Reason for revert:
results in a scavenge storm if scavenge doesn't free enough memory

Original issue's description:
> Let GC select the collector when the external memory allocation limit is reached
>
> BUG=none
> R=hpayer@chromium.org
> LOG=n
>
> Committed: https://crrev.com/93d6216099b60e95bc816bcc913f8f841ee795b6
> Cr-Commit-Position: refs/heads/master@{#29235}

TBR=hpayer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none

Review URL: https://codereview.chromium.org/1215513004

Cr-Commit-Position: refs/heads/master@{#29383}