Reland of permissions: add layout tests for multiple requests

Reland of permissions: add layout tests for multiple requests (patchset #1 id:1 of https://codereview.chromium.org/1376523006/ )

Reason for revert:
Relanding and disabling the test on Win 7 in order to have tests and investigate the problem.

Original issue's description:
> Revert of permissions: add layout tests for multiple requests (patchset #2 id:20001 of https://codereview.chromium.org/1381023003/ )
>
> Reason for revert:
> BUG=538717
>
> Original issue's description:
> > permissions: add layout tests for multiple requests
> >
> > No permisisons, single, multiple and duplicate permissions
> > are all tested. Permission updates being reflected in the request
> > is also tested.
> >
> > BUG=516626
> >
> > Committed: https://crrev.com/4a5a84a2a326cecc6d183478ca684aea753adc18
> > Cr-Commit-Position: refs/heads/master@{#352015}
>
> TBR=mlamouri@chromium.org,lalitm@google.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=516626
>
> Committed: https://crrev.com/0adc11742287c2af556837823aebccd8c2961bc4
> Cr-Commit-Position: refs/heads/master@{#352115}

TBR=lalitm@google.com,dmurph@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=538717
Committed: https://crrev.com/a9a921ac00d3a419ace22e177d855bc2e445f536
Cr-Commit-Position: refs/heads/master@{#352255}

[mlamouri (slow - plz ping), 2015-10-03 14:51:27]

Created Reland of permissions: add layout tests for multiple requests

[commit-bot: I haz the power, 2015-10-03 14:51:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1384163002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1384163002/1

[commit-bot: I haz the power, 2015-10-03 14:52:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-03 14:52:58]

Patchset 1 (id:??) landed as
https://crrev.com/a9a921ac00d3a419ace22e177d855bc2e445f536
Cr-Commit-Position: refs/heads/master@{#352255}