Revert of Add script context with context-allocated "const this"

Revert of Add script context with context-allocated "const this" (patchset #2 id:20001 of https://codereview.chromium.org/1173333004/)

Reason for revert:
nosnap failure

Original issue's description:
> Add script context with context-allocated "const this"
>
> This is a reapplication of https://codereview.chromium.org/1179893002/.
>
> R=rossberg@chromium.org,mstarzinger@chromium.org
> LOG=N
> BUG=498811
>
> Committed: https://crrev.com/cfc764f4050edc74aef92daa4c39ccc113893968
> Cr-Commit-Position: refs/heads/master@{#28994}

TBR=mstarzinger@chromium.org,rossberg@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=498811
Committed: https://crrev.com/7063ed2de68c56f03667009dffa7b808c0dc170c
Cr-Commit-Position: refs/heads/master@{#28996}

[wingo, 2015-06-12 11:52:43]

Created Revert of Add script context with context-allocated "const this"

[commit-bot: I haz the power, 2015-06-12 11:52:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1177903004/1

[commit-bot: I haz the power, 2015-06-12 11:53:09]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-12 11:53:21]

Patchset 1 (id:??) landed as
https://crrev.com/7063ed2de68c56f03667009dffa7b808c0dc170c
Cr-Commit-Position: refs/heads/master@{#28996}