cleanup/ Remove deprecated extension notification from policy_browsertest.cc

cleanup/ Remove deprecated extension notification from policy_browsertest.cc

BUG=411568
TEST=browser_tests --gtest_filter=PolicyTest.*

Committed: https://crrev.com/8fec6610ed298d29710286055bc2bb1e16e75c04
Cr-Commit-Position: refs/heads/master@{#353502}

[limasdf, 2015-10-11 05:34:56]

Patchset #1 (id:1) has been deleted

[limasdf, 2015-10-11 05:39:07]

limasdf@gmail.com changed reviewers:
+ cschuet@chromium.org

[limasdf, 2015-10-11 05:39:37]

Please take a look

[cschuet (SLOW), 2015-10-12 09:15:31]

On 2015/10/11 05:39:37, limasdf wrote:
> Please take a look

LGTM. Thanks for cleaning this up.

[limasdf, 2015-10-12 09:16:22]

The CQ bit was checked by limasdf@gmail.com

[commit-bot: I haz the power, 2015-10-12 09:16:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1390903006/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1390903006/20001

[commit-bot: I haz the power, 2015-10-12 10:03:15]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2015-10-12 10:04:23]

Patchset 1 (id:??) landed as
https://crrev.com/8fec6610ed298d29710286055bc2bb1e16e75c04
Cr-Commit-Position: refs/heads/master@{#353502}