exo: Fix surface origin offset.

exo: Fix surface origin offset.

GetWindowBoundsInScreen() should never be used to determine
the surface origin as it takes ancestor transforms into
account. Surface origin should be relative to widget window
bounds as they are not affected by transforms.

BUG=549781
TEST=exo_unittests
TBR=dcastagna@chromium.org

Committed: https://crrev.com/9951be0bad4f2e88fbb2e8e1d17f43c395ffdad5
Cr-Commit-Position: refs/heads/master@{#397994}

[reveman, 2016-06-06 08:36:59]

The CQ bit was checked by reveman@chromium.org

[commit-bot: I haz the power, 2016-06-06 08:37:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2045433002/1

[commit-bot: I haz the power, 2016-06-06 09:11:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-06 09:13:20]

Description was changed from

==========
exo: Fix surface origin offset.

GetWindowBoundsInScreen() should never be used to determine
the surface origin as it takes ancestor transforms into
account. Surface origin should be relative to widget window
bounds as they are not affected by transforms.

BUG=549781
TEST=exo_unittests
TBR=dcastagna@chromium.org
==========

to

==========
exo: Fix surface origin offset.

GetWindowBoundsInScreen() should never be used to determine
the surface origin as it takes ancestor transforms into
account. Surface origin should be relative to widget window
bounds as they are not affected by transforms.

BUG=549781
TEST=exo_unittests
TBR=dcastagna@chromium.org

Committed: https://crrev.com/9951be0bad4f2e88fbb2e8e1d17f43c395ffdad5
Cr-Commit-Position: refs/heads/master@{#397994}
==========

[commit-bot: I haz the power, 2016-06-06 09:13:21]

Patchset 1 (id:??) landed as
https://crrev.com/9951be0bad4f2e88fbb2e8e1d17f43c395ffdad5
Cr-Commit-Position: refs/heads/master@{#397994}