Adds WindowManagerManager to mus

Adds WindowManagerManager to mus

WindowTreeHostImpl now has a set of WindowManagerManagers. There are
two distinct modes:
. Created by way of using WindowTreeHostFactory. In this mode there is
  only one WindowManagerManager for the host.
. Created implicitly when no WindowTreeHostFactorys have been used. In
  this mode there is a WindowManagerManager per userid.

This patch doesn't enforce WindowTreeClients only created windows
under the WindowManager with the id. That'll come after
this. Additionally there is a lot of cleanup to do, but I'm trying to
minimize the extent of the changes, which are already quite large.

I've changed mash (desktop_wm) so that it no longer
uses WindowTreeHostFactory. This triggers having mus create a default
WindowTreeHost (the second mode above).

BUG=590955
TEST=covered by tests
R=ben@chromium.org
BUG=

Committed: https://crrev.com/cbe425b94131041e3a754c18c269702acd624880
Cr-Commit-Position: refs/heads/master@{#378809}

[Ben Goodger (Google), 2016-03-02 18:58:36]

lgtm, just choose a better name than WindowManagerManager.

[sky, 2016-03-02 19:24:40]

The CQ bit was checked by sky@chromium.org

[sky, 2016-03-02 19:24:41]

The patchset sent to the CQ was uploaded after l-g-t-m from ben@chromium.org
Link to the patchset: https://codereview.chromium.org/1755223002/#ps20001
(title: "merge and WindowManagerState")

[commit-bot: I haz the power, 2016-03-02 19:25:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1755223002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1755223002/20001

[commit-bot: I haz the power, 2016-03-02 20:04:39]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-02 20:06:06]

Description was changed from

==========
Adds WindowManagerManager to mus

WindowTreeHostImpl now has a set of WindowManagerManagers. There are
two distinct modes:
. Created by way of using WindowTreeHostFactory. In this mode there is
  only one WindowManagerManager for the host.
. Created implicitly when no WindowTreeHostFactorys have been used. In
  this mode there is a WindowManagerManager per userid.

This patch doesn't enforce WindowTreeClients only created windows
under the WindowManager with the id. That'll come after
this. Additionally there is a lot of cleanup to do, but I'm trying to
minimize the extent of the changes, which are already quite large.

I've changed mash (desktop_wm) so that it no longer
uses WindowTreeHostFactory. This triggers having mus create a default
WindowTreeHost (the second mode above).

BUG=590955
TEST=covered by tests
R=ben@chromium.org
BUG=
==========

to

==========
Adds WindowManagerManager to mus

WindowTreeHostImpl now has a set of WindowManagerManagers. There are
two distinct modes:
. Created by way of using WindowTreeHostFactory. In this mode there is
  only one WindowManagerManager for the host.
. Created implicitly when no WindowTreeHostFactorys have been used. In
  this mode there is a WindowManagerManager per userid.

This patch doesn't enforce WindowTreeClients only created windows
under the WindowManager with the id. That'll come after
this. Additionally there is a lot of cleanup to do, but I'm trying to
minimize the extent of the changes, which are already quite large.

I've changed mash (desktop_wm) so that it no longer
uses WindowTreeHostFactory. This triggers having mus create a default
WindowTreeHost (the second mode above).

BUG=590955
TEST=covered by tests
R=ben@chromium.org
BUG=

Committed: https://crrev.com/cbe425b94131041e3a754c18c269702acd624880
Cr-Commit-Position: refs/heads/master@{#378809}
==========

[commit-bot: I haz the power, 2016-03-02 20:06:07]

Patchset 2 (id:??) landed as
https://crrev.com/cbe425b94131041e3a754c18c269702acd624880
Cr-Commit-Position: refs/heads/master@{#378809}