Unregister from network changes on destroy in ContextualSearchTabHelper

Unregister from network changes on destroy in ContextualSearchTabHelper

This causes us to leak ChromeActivity instances and all the views
associated with them. In general we should always make sure to
unregister notifiers from application level singletons on destroy.

BUG=710612
Review-Url: https://codereview.chromium.org/2812143002
Cr-Commit-Position: refs/heads/master@{#463855}
Committed: https://chromium.googlesource.com/chromium/src/+/810b810269e4329d50c089c26d77f47ea89b61ef

[Yusuf, 2017-04-11 22:07:28]

yusufo@chromium.org changed reviewers:
+ tedchoc@chromium.org

[Ted C, 2017-04-11 22:31:44]

lgtm

[Yusuf, 2017-04-11 23:32:40]

The CQ bit was checked by yusufo@chromium.org

[commit-bot: I haz the power, 2017-04-11 23:33:40]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-12 00:25:35]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1491953560272520, "parent_rev":
"fb19fb99a92bd5335dd24dde693e64f8ced55cbf", "commit_rev":
"810b810269e4329d50c089c26d77f47ea89b61ef"}

[commit-bot: I haz the power, 2017-04-12 00:30:46]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1491953560272520, "parent_rev":
"fb19fb99a92bd5335dd24dde693e64f8ced55cbf", "commit_rev":
"810b810269e4329d50c089c26d77f47ea89b61ef"}

[commit-bot: I haz the power, 2017-04-12 00:30:51]

Description was changed from

==========
Unregister from network changes on destroy in ContextualSearchTabHelper

This causes us to leak ChromeActivity instances and all the views
associated with them. In general we should always make sure to
unregister notifiers from application level singletons on destroy.

BUG=710612
==========

to

==========
Unregister from network changes on destroy in ContextualSearchTabHelper

This causes us to leak ChromeActivity instances and all the views
associated with them. In general we should always make sure to
unregister notifiers from application level singletons on destroy.

BUG=710612

Review-Url: https://codereview.chromium.org/2812143002
Cr-Commit-Position: refs/heads/master@{#463855}
Committed:
https://chromium.googlesource.com/chromium/src/+/810b810269e4329d50c089c26d77...
==========

[commit-bot: I haz the power, 2017-04-12 00:30:53]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/810b810269e4329d50c089c26d77...