Remove FrameSinkId hierarchy when unparenting ServerWindow.

Remove FrameSinkId hierarchy when unparenting ServerWindow.

We need to change the FrameSinkId heirarchy along with ServerWindow
hierarchy. We were missing a case when we unparent a ServerWindow.

This caused a crash in app list because we never unregister the
FrameSinkId heirarchy. There is a DCHECK that we don't register the same
hierarchy twice and when reopening the app list that DCHECK was hit.

BUG=690970
Review-Url: https://codereview.chromium.org/2692223003
Cr-Commit-Position: refs/heads/master@{#450427}
Committed: https://chromium.googlesource.com/chromium/src/+/509840116ed907fb1e466c7ca0a35eb76f0eb6d5

[kylechar, 2017-02-14 16:49:17]

kylechar@chromium.org changed reviewers:
+ msw@chromium.org

[msw, 2017-02-14 17:01:03]

Nice! lgtm. Talk about an instant turnaround with crbug.com/673030 :)

[kylechar, 2017-02-14 17:01:37]

The CQ bit was checked by kylechar@chromium.org

[commit-bot: I haz the power, 2017-02-14 17:02:34]

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, 2017-02-14 19:13:44]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1487091697715050, "parent_rev":
"d88402de3d2c62509fe5d096e36e8190cee3e5d8", "commit_rev":
"509840116ed907fb1e466c7ca0a35eb76f0eb6d5"}

[commit-bot: I haz the power, 2017-02-14 19:14:24]

Description was changed from

==========
Remove FrameSinkId hierarchy when unparenting ServerWindow.

We need to change the FrameSinkId heirarchy along with ServerWindow
hierarchy. We were missing a case when we unparent a ServerWindow.

This caused a crash in app list because we never unregister the
FrameSinkId heirarchy. There is a DCHECK that we don't register the same
hierarchy twice and when reopening the app list that DCHECK was hit.

BUG=690970
==========

to

==========
Remove FrameSinkId hierarchy when unparenting ServerWindow.

We need to change the FrameSinkId heirarchy along with ServerWindow
hierarchy. We were missing a case when we unparent a ServerWindow.

This caused a crash in app list because we never unregister the
FrameSinkId heirarchy. There is a DCHECK that we don't register the same
hierarchy twice and when reopening the app list that DCHECK was hit.

BUG=690970

Review-Url: https://codereview.chromium.org/2692223003
Cr-Commit-Position: refs/heads/master@{#450427}
Committed:
https://chromium.googlesource.com/chromium/src/+/509840116ed907fb1e466c7ca0a3...
==========

[commit-bot: I haz the power, 2017-02-14 19:14:27]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/509840116ed907fb1e466c7ca0a3...