Break dependency between ash::DisplayManager and ash::ScreenAsh

Break dependency between ash::DisplayManager and ash::ScreenAsh

As part of preparing ash::DisplayManager for relocation to
ui::display, remove its dependency on ash::ScreenAsh and instead
inject the Screen implementation at the time of construction.
Eventually, ash::DisplayManager will be in ui::display and existing
ash (via ash::ScreenAsh) or mus (via ws::display::PlatformScreen) will
inject an appropriate display::Screen implementation.

BUG=581462
Committed: https://crrev.com/2c930540bac9acebd1419e87e3a61c1fa5d59a6d
Cr-Commit-Position: refs/heads/master@{#416792}

[rjkroege, 2016-08-31 01:52:19]

rjkroege@chromium.org changed reviewers:
+ oshima@chromium.org

[rjkroege, 2016-08-31 01:52:20]

ptal

[oshima, 2016-08-31 22:53:55]

lgtm

[rjkroege, 2016-09-06 23:24:58]

The CQ bit was checked by rjkroege@chromium.org

[rjkroege, 2016-09-06 23:24:59]

The patchset sent to the CQ was uploaded after l-g-t-m from oshima@chromium.org
Link to the patchset: https://codereview.chromium.org/2294853003/#ps20001
(title: "rebased")

[commit-bot: I haz the power, 2016-09-06 23:25:23]

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, 2016-09-07 00:22:03]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-07 00:24:13]

Description was changed from

==========
Break dependency between ash::DisplayManager and ash::ScreenAsh

As part of preparing ash::DisplayManager for relocation to
ui::display, remove its dependency on ash::ScreenAsh and instead
inject the Screen implementation at the time of construction.
Eventually, ash::DisplayManager will be in ui::display and existing
ash (via ash::ScreenAsh) or mus (via ws::display::PlatformScreen) will
inject an appropriate display::Screen implementation.

BUG=581462
==========

to

==========
Break dependency between ash::DisplayManager and ash::ScreenAsh

As part of preparing ash::DisplayManager for relocation to
ui::display, remove its dependency on ash::ScreenAsh and instead
inject the Screen implementation at the time of construction.
Eventually, ash::DisplayManager will be in ui::display and existing
ash (via ash::ScreenAsh) or mus (via ws::display::PlatformScreen) will
inject an appropriate display::Screen implementation.

BUG=581462

Committed: https://crrev.com/2c930540bac9acebd1419e87e3a61c1fa5d59a6d
Cr-Commit-Position: refs/heads/master@{#416792}
==========

[commit-bot: I haz the power, 2016-09-07 00:24:14]

Patchset 2 (id:??) landed as
https://crrev.com/2c930540bac9acebd1419e87e3a61c1fa5d59a6d
Cr-Commit-Position: refs/heads/master@{#416792}