exo: Clean up cursor code

exo: Clean up cursor code

This CL fixes an omission in WMHelper observer registration, as well as
an incorrect DCHECK on aura::client::GetCursorClient. It also cleans up
repetitive null checks and typos.

BUG=642894
TEST=None

Review-Url: https://codereview.chromium.org/2778913002
Cr-Commit-Position: refs/heads/master@{#461023}
Committed: https://chromium.googlesource.com/chromium/src/+/fcec89d6f03db12e55e42db9d5bfc9a0d7edbc99

[Dominik Laskowski, 2017-03-27 21:42:17]

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

[commit-bot: I haz the power, 2017-03-27 21:42:53]

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

[Dominik Laskowski, 2017-03-27 21:43:01]

domlaskowski@chromium.org changed reviewers:
+ reveman@chromium.org

[Dominik Laskowski, 2017-03-27 21:43:02]

PTAL. Split from https://codereview.chromium.org/2780623002/

[commit-bot: I haz the power, 2017-03-27 22:35:52]

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

[commit-bot: I haz the power, 2017-03-27 22:35:54]

Dry run: This issue passed the CQ dry run.

[reveman, 2017-03-28 07:25:16]

lgtm % nit

https://codereview.chromium.org/2778913002/diff/1/components/exo/shell_surfac...
File components/exo/shell_surface.cc (right):

https://codereview.chromium.org/2778913002/diff/1/components/exo/shell_surfac...
components/exo/shell_surface.cc:1304: if (auto* cursor_client =
nit: this is a change in behavior (we asserted the cursor client is set before)
and I'm not a fan of assignment inside conditionals. please restore structure as
before and if the change in behavior is needed then explain why

[Dominik Laskowski, 2017-03-30 01:01:18]

https://codereview.chromium.org/2778913002/diff/1/components/exo/shell_surfac...
File components/exo/shell_surface.cc (right):

https://codereview.chromium.org/2778913002/diff/1/components/exo/shell_surfac...
components/exo/shell_surface.cc:1304: if (auto* cursor_client =
On 2017/03/28 07:25:15, reveman wrote:
> nit: this is a change in behavior (we asserted the cursor client is set
before)
> and I'm not a fan of assignment inside conditionals. please restore structure
as
> before and if the change in behavior is needed then explain why 

Restored. The DCHECK is technically correct, since in theory GetCursorClient
should never return null for root windows. However, it currently returns null in
Mus. Also, this is the only caller that makes the non-null assumption, which is
confusing.

On second thought, the drag should not be started in this case, so I've replaced
the DCHECK with an early return.

[reveman, 2017-03-30 07:15:00]

On 2017/03/30 at 01:01:18, domlaskowski wrote:
>
https://codereview.chromium.org/2778913002/diff/1/components/exo/shell_surfac...
> File components/exo/shell_surface.cc (right):
> 
>
https://codereview.chromium.org/2778913002/diff/1/components/exo/shell_surfac...
> components/exo/shell_surface.cc:1304: if (auto* cursor_client =
> On 2017/03/28 07:25:15, reveman wrote:
> > nit: this is a change in behavior (we asserted the cursor client is set
before)
> > and I'm not a fan of assignment inside conditionals. please restore
structure as
> > before and if the change in behavior is needed then explain why 
> 
> Restored. The DCHECK is technically correct, since in theory GetCursorClient
should never return null for root windows. However, it currently returns null in
Mus. Also, this is the only caller that makes the non-null assumption, which is
confusing.
> 
> On second thought, the drag should not be started in this case, so I've
replaced the DCHECK with an early return.

Ok, early return for consistency sgtm. LGTM.

[Dominik Laskowski, 2017-03-31 00:26:38]

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

[commit-bot: I haz the power, 2017-03-31 00:27:36]

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, 2017-03-31 01:07:07]

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

[commit-bot: I haz the power, 2017-03-31 01:07:08]

Dry run: This issue passed the CQ dry run.

[Dominik Laskowski, 2017-03-31 02:15:31]

The CQ bit was checked by domlaskowski@chromium.org

[Dominik Laskowski, 2017-03-31 02:15:31]

The patchset sent to the CQ was uploaded after l-g-t-m from reveman@chromium.org
Link to the patchset: https://codereview.chromium.org/2778913002/#ps40001
(title: "Rebase")

[commit-bot: I haz the power, 2017-03-31 02:16:06]

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, 2017-03-31 02:26:56]

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

[commit-bot: I haz the power, 2017-03-31 02:26:57]

Try jobs failed on following builders:
  chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Dominik Laskowski, 2017-03-31 03:43:11]

The CQ bit was checked by domlaskowski@chromium.org

[Dominik Laskowski, 2017-03-31 03:43:11]

The patchset sent to the CQ was uploaded after l-g-t-m from reveman@chromium.org
Link to the patchset: https://codereview.chromium.org/2778913002/#ps60001
(title: "Rebase")

[commit-bot: I haz the power, 2017-03-31 03:43:47]

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, 2017-03-31 04:17:17]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1490931791258410,
"parent_rev": "0d65c79254abc0ca2cad40bc495d7f92ca1f0b9c", "commit_rev":
"fcec89d6f03db12e55e42db9d5bfc9a0d7edbc99"}

[commit-bot: I haz the power, 2017-03-31 04:18:07]

Description was changed from

==========
exo: Clean up cursor code

This CL fixes an omission in WMHelper observer registration, as well as
an incorrect DCHECK on aura::client::GetCursorClient. It also cleans up
repetitive null checks and typos.

BUG=642894
TEST=None
==========

to

==========
exo: Clean up cursor code

This CL fixes an omission in WMHelper observer registration, as well as
an incorrect DCHECK on aura::client::GetCursorClient. It also cleans up
repetitive null checks and typos.

BUG=642894
TEST=None

Review-Url: https://codereview.chromium.org/2778913002
Cr-Commit-Position: refs/heads/master@{#461023}
Committed:
https://chromium.googlesource.com/chromium/src/+/fcec89d6f03db12e55e42db9d5bf...
==========

[commit-bot: I haz the power, 2017-03-31 04:18:08]

Committed patchset #4 (id:60001) as
https://chromium.googlesource.com/chromium/src/+/fcec89d6f03db12e55e42db9d5bf...