Revert of Let GC select the collector when the external memory allocation limit is reached

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

Committed: https://crrev.com/5344fe517cdc0738e2f9c2af5153654409e527ac
Cr-Commit-Position: refs/heads/master@{#29383}

[jochen (gone - plz use gerrit), 2015-06-30 15:14:16]

Created Revert of Let GC select the collector when the external memory
allocation limit is reached

[commit-bot: I haz the power, 2015-06-30 15:14:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1215513004/1

[commit-bot: I haz the power, 2015-06-30 15:14:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-30 15:15:04]

Patchset 1 (id:??) landed as
https://crrev.com/5344fe517cdc0738e2f9c2af5153654409e527ac
Cr-Commit-Position: refs/heads/master@{#29383}