[ios] Add a BrowserListObserver interface.

[ios] Add a BrowserListObserver interface.

In order to serialise the state of the application, it is necessary
to track creation and destruction of WebStateLists. This is done
by adding a BrowserListObserver to track the creation of owning
Browsers.

BUG=710848
Review-Url: https://codereview.chromium.org/2831363002
Cr-Commit-Position: refs/heads/master@{#468930}
Committed: https://chromium.googlesource.com/chromium/src/+/b65a25e558ff3d3f3e411e3aa2fb09cab0fe2ca1

[sdefresne, 2017-04-21 15:30:32]

The CQ bit was checked by sdefresne@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-21 15:30:58]

Dry run: 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, 2017-04-21 16:36:29]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-21 16:36:30]

Dry run: This issue passed the CQ dry run.

[sdefresne, 2017-04-25 16:07:03]

The CQ bit was checked by sdefresne@chromium.org to run a CQ dry run

[sdefresne, 2017-04-25 16:07:13]

Patchset #1 (id:1) has been deleted

[commit-bot: I haz the power, 2017-04-25 16:07:22]

Dry run: CQ is trying da patch.

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

[sdefresne, 2017-04-25 16:07:34]

sdefresne@chromium.org changed reviewers:
+ rohitrao@chromium.org

[sdefresne, 2017-04-25 16:07:34]

Please take a look and send to CQ if LGTY.

[commit-bot: I haz the power, 2017-04-25 17:50:07]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-25 17:50:07]

Dry run: This issue passed the CQ dry run.

[sdefresne, 2017-04-27 13:26:02]

rohitrao: ping

[sdefresne, 2017-05-02 07:51:15]

rohitrao: ping

[rohitrao (ping after 24h), 2017-05-02 10:10:29]

lgtm

Why is this needed?

[sdefresne, 2017-05-02 13:48:43]

Description was changed from

==========
[ios] Add a BrowserListObserver interface.

BUG=710848
==========

to

==========
[ios] Add a BrowserListObserver interface.

In order to serialise the state of the application, it is necessary
to track creation and destruction of WebStateLists. This is done
by adding a BrowserListObserver to track the creation of owning
Browsers.

BUG=710848
==========

[sdefresne, 2017-05-02 13:48:50]

On 2017/05/02 10:10:29, rohitrao (ping after 24h) wrote:
> lgtm
> 
> Why is this needed?

For serialisation it is necessary to track creation of WebStateLists. The
easiest way to do this is to track creation of Browsers, thus the
BrowserListObserver interface. I've updated the description.

[sdefresne, 2017-05-02 15:07:46]

The CQ bit was checked by sdefresne@chromium.org

[sdefresne, 2017-05-02 15:07:47]

The patchset sent to the CQ was uploaded after l-g-t-m from
rohitrao@chromium.org
Link to the patchset: https://codereview.chromium.org/2831363002/#ps40001
(title: "Rebase.")

[commit-bot: I haz the power, 2017-05-02 15:08:21]

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, 2017-05-02 16:23:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-02 16:23:20]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[sdefresne, 2017-05-03 08:12:10]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2017-05-03 08:12:28]

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, 2017-05-03 08:56:40]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-03 08:56:41]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[sdefresne, 2017-05-03 09:04:49]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2017-05-03 09:05:00]

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, 2017-05-03 09:31:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-05-03 09:31:46]

Try jobs failed on following builders:
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[sdefresne, 2017-05-03 10:10:57]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2017-05-03 10:11:04]

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, 2017-05-03 10:33:39]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1493806257738330,
"parent_rev": "6561c2f12d7c6d68613da7500643b300b923e15b", "commit_rev":
"b65a25e558ff3d3f3e411e3aa2fb09cab0fe2ca1"}

[commit-bot: I haz the power, 2017-05-03 10:33:57]

Description was changed from

==========
[ios] Add a BrowserListObserver interface.

In order to serialise the state of the application, it is necessary
to track creation and destruction of WebStateLists. This is done
by adding a BrowserListObserver to track the creation of owning
Browsers.

BUG=710848
==========

to

==========
[ios] Add a BrowserListObserver interface.

In order to serialise the state of the application, it is necessary
to track creation and destruction of WebStateLists. This is done
by adding a BrowserListObserver to track the creation of owning
Browsers.

BUG=710848

Review-Url: https://codereview.chromium.org/2831363002
Cr-Commit-Position: refs/heads/master@{#468930}
Committed:
https://chromium.googlesource.com/chromium/src/+/b65a25e558ff3d3f3e411e3aa2fb...
==========

[commit-bot: I haz the power, 2017-05-03 10:33:59]

Committed patchset #2 (id:40001) as
https://chromium.googlesource.com/chromium/src/+/b65a25e558ff3d3f3e411e3aa2fb...