Experimental: remove duplicate script scope.

Remove duplicate script scope.

We previously had two nested SCRIPT_SCOPEs (used to be GLOBAL_SCOPES), but as
the lexical variable implementation changed, the inner one is no longer needed.
BUG=

Committed: https://crrev.com/0c56d7e8092e130cb1c6c11cfa18dc968f74d131
Cr-Commit-Position: refs/heads/master@{#27176}

[Dmitry Lomov (no reviews), 2015-03-13 09:33:14]

dslomov@chromium.org changed reviewers:
+ dslomov@chromium.org

[Dmitry Lomov (no reviews), 2015-03-13 09:33:14]

lgtm if tests pass

[marja, 2015-03-13 09:43:43]

The CQ bit was checked by marja@chromium.org

[commit-bot: I haz the power, 2015-03-13 09:43:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1002193002/1

[commit-bot: I haz the power, 2015-03-13 09:46:11]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-13 09:46:21]

Patchset 1 (id:??) landed as
https://crrev.com/0c56d7e8092e130cb1c6c11cfa18dc968f74d131
Cr-Commit-Position: refs/heads/master@{#27176}