Revert of Disable support for swapped out RenderFrame(Host)

Revert of Disable support for swapped out RenderFrame(Host) (patchset #6 id:120001 of https://codereview.chromium.org/1381443003/ )

Reason for revert:
Speculative revert to see if crashes hit in crbug.com/541578 will disappear.

Original issue's description:
> Disable support for swapped out RenderFrame(Host)
>
> Another attempt at disabling swapped out. The crashes and bugs found during the first attempt should be fixed now.
>
> BUG=357747
>
> Committed: https://crrev.com/aa836bae06656808d56e0afde4944b6dcca97a10
> Cr-Commit-Position: refs/heads/master@{#353055}

TBR=creis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=357747
Committed: https://crrev.com/2f50210f15adbfde970bbfaeba6271d71e3fce32
Cr-Commit-Position: refs/heads/master@{#353434}

[nasko, 2015-10-10 00:25:11]

Created Revert of Disable support for swapped out RenderFrame(Host)

[commit-bot: I haz the power, 2015-10-10 00:28:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1394373003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1394373003/1

[commit-bot: I haz the power, 2015-10-10 00:34:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1394373003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1394373003/1

[commit-bot: I haz the power, 2015-10-10 00:38:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-10 00:39:30]

Patchset 1 (id:??) landed as
https://crrev.com/2f50210f15adbfde970bbfaeba6271d71e3fce32
Cr-Commit-Position: refs/heads/master@{#353434}