services/ui: Fix setting client id for gpu channels.

services/ui: Fix setting client id for gpu channels.

This fixes a race in setting the client id for the gpu channels for mus
clients. This race can happen if client requests for gpu channels start
coming in to the window server, before the gpu service is initialized
and the ws is notified. This race was causing the gpu channels in mus
clients to get dropped, leading to unexpected crashes.

BUG=649567
Committed: https://crrev.com/6616407d2d6f64c18234c08cdda042827b7295c1
Cr-Commit-Position: refs/heads/master@{#422109}

[sadrul, 2016-09-30 04:25:57]

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

[commit-bot: I haz the power, 2016-09-30 04:26:13]

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

[sadrul, 2016-09-30 04:26:32]

sadrul@chromium.org changed reviewers:
+ fsamuel@chromium.org

[commit-bot: I haz the power, 2016-09-30 05:16:08]

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

[commit-bot: I haz the power, 2016-09-30 05:16:09]

Dry run: This issue passed the CQ dry run.

[Fady Samuel, 2016-09-30 13:34:32]

So a mus client would end up with the same client ID as the internal channel?
And of course the GPU service would get confused and things crash? Heh, I see.
Weird how we were setting next_client_id_. LGTM

[sadrul, 2016-09-30 14:42:38]

The CQ bit was checked by sadrul@chromium.org

[commit-bot: I haz the power, 2016-09-30 14:43:00]

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, 2016-09-30 14:48:06]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-30 14:50:00]

Description was changed from

==========
services/ui: Fix setting client id for gpu channels.

This fixes a race in setting the client id for the gpu channels for mus
clients. This race can happen if client requests for gpu channels start
coming in to the window server, before the gpu service is initialized
and the ws is notified. This race was causing the gpu channels in mus
clients to get dropped, leading to unexpected crashes.

BUG=649567
==========

to

==========
services/ui: Fix setting client id for gpu channels.

This fixes a race in setting the client id for the gpu channels for mus
clients. This race can happen if client requests for gpu channels start
coming in to the window server, before the gpu service is initialized
and the ws is notified. This race was causing the gpu channels in mus
clients to get dropped, leading to unexpected crashes.

BUG=649567

Committed: https://crrev.com/6616407d2d6f64c18234c08cdda042827b7295c1
Cr-Commit-Position: refs/heads/master@{#422109}
==========

[commit-bot: I haz the power, 2016-09-30 14:50:01]

Patchset 1 (id:??) landed as
https://crrev.com/6616407d2d6f64c18234c08cdda042827b7295c1
Cr-Commit-Position: refs/heads/master@{#422109}