Fix DCHECK/crash in WindowManagerState

Fix DCHECK/crash in WindowManagerState

On linux we can get events outside the bounds of the window, which
causes problems for WindowManagerState. This fixes that.

BUG=none
TEST=none
R=ben@chromium.org

Committed: https://crrev.com/94838bc0326ade3c225ee1c0597d6c5d44a9c0b1
Cr-Commit-Position: refs/heads/master@{#380456}

[sky, 2016-03-10 19:27:32]

I'll add a test separately, but this is causing DCHECKs so want to land a fix
asap.

[Ben Goodger (Google), 2016-03-10 19:57:31]

lgtm

[sky, 2016-03-10 20:07:14]

The CQ bit was checked by sky@chromium.org

[commit-bot: I haz the power, 2016-03-10 20:07:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1783553004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1783553004/1

[commit-bot: I haz the power, 2016-03-10 20:42:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-10 20:43:53]

Description was changed from

==========
Fix DCHECK/crash in WindowManagerState

On linux we can get events outside the bounds of the window, which
causes problems for WindowManagerState. This fixes that.

BUG=none
TEST=none
R=ben@chromium.org
==========

to

==========
Fix DCHECK/crash in WindowManagerState

On linux we can get events outside the bounds of the window, which
causes problems for WindowManagerState. This fixes that.

BUG=none
TEST=none
R=ben@chromium.org

Committed: https://crrev.com/94838bc0326ade3c225ee1c0597d6c5d44a9c0b1
Cr-Commit-Position: refs/heads/master@{#380456}
==========

[commit-bot: I haz the power, 2016-03-10 20:43:54]

Patchset 1 (id:??) landed as
https://crrev.com/94838bc0326ade3c225ee1c0597d6c5d44a9c0b1
Cr-Commit-Position: refs/heads/master@{#380456}