Revert of Mus Demo: Move definition of WindowTreeData into separate files.

Revert of Mus Demo: Move definition of WindowTreeData into separate files. (patchset #4 id:60001 of https://codereview.chromium.org/2694843005/ )

Reason for revert:
This change appears to have broken the compile step of the following build:

https://build.chromium.org/p/chromium/builders/Win%20x64/builds/8536

Original issue's description:
> Mus Demo: Move definition of WindowTreeData into mus_demo.h
> 
> In follow-up CLs, MusDemo will be split into two derived classes
> demonstrating external and internal modes. These classes will handle
> instances of WindowTreeData and for that purpose this CL moves the
> definition of WindowTreeData into separate files. We also adjust a bit
> the Constructor/Init to help in future CLs.
> 
> BUG=666958
> R=kylechar@chromium.org
> 
> Review-Url: https://codereview.chromium.org/2694843005
> Cr-Commit-Position: refs/heads/master@{#450726}
> Committed: https://chromium.googlesource.com/chromium/src/+/da4637b0c789f6360dacdea216dd5316972862ee

TBR=kylechar@chromium.org,fwang@igalia.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=666958
Review-Url: https://codereview.chromium.org/2694413003
Cr-Commit-Position: refs/heads/master@{#450742}
Committed: https://chromium.googlesource.com/chromium/src/+/03f2053328cb3ab19f5c5a0348cc3581576bbe49

[bruthig, 2017-02-15 18:22:05]

The CQ bit was checked by bruthig@chromium.org

[bruthig, 2017-02-15 18:22:06]

Created Revert of Mus Demo: Move definition of WindowTreeData into separate
files.

[commit-bot: I haz the power, 2017-02-15 18:22:56]

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, 2017-02-15 18:23:42]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1487182925070660, "parent_rev":
"064a292ce35b28592529c5bded26f905d65833a9", "commit_rev":
"03f2053328cb3ab19f5c5a0348cc3581576bbe49"}

[commit-bot: I haz the power, 2017-02-15 18:24:22]

Description was changed from

==========
Revert of Mus Demo: Move definition of WindowTreeData into separate files.
(patchset #4 id:60001 of https://codereview.chromium.org/2694843005/ )

Reason for revert:
This change appears to have broken the compile step of the following build:

https://build.chromium.org/p/chromium/builders/Win%20x64/builds/8536

Original issue's description:
> Mus Demo: Move definition of WindowTreeData into mus_demo.h
> 
> In follow-up CLs, MusDemo will be split into two derived classes
> demonstrating external and internal modes. These classes will handle
> instances of WindowTreeData and for that purpose this CL moves the
> definition of WindowTreeData into separate files. We also adjust a bit
> the Constructor/Init to help in future CLs.
> 
> BUG=666958
> R=kylechar@chromium.org
> 
> Review-Url: https://codereview.chromium.org/2694843005
> Cr-Commit-Position: refs/heads/master@{#450726}
> Committed:
https://chromium.googlesource.com/chromium/src/+/da4637b0c789f6360dacdea216dd...

TBR=kylechar@chromium.org,fwang@igalia.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=666958
==========

to

==========
Revert of Mus Demo: Move definition of WindowTreeData into separate files.
(patchset #4 id:60001 of https://codereview.chromium.org/2694843005/ )

Reason for revert:
This change appears to have broken the compile step of the following build:

https://build.chromium.org/p/chromium/builders/Win%20x64/builds/8536

Original issue's description:
> Mus Demo: Move definition of WindowTreeData into mus_demo.h
> 
> In follow-up CLs, MusDemo will be split into two derived classes
> demonstrating external and internal modes. These classes will handle
> instances of WindowTreeData and for that purpose this CL moves the
> definition of WindowTreeData into separate files. We also adjust a bit
> the Constructor/Init to help in future CLs.
> 
> BUG=666958
> R=kylechar@chromium.org
> 
> Review-Url: https://codereview.chromium.org/2694843005
> Cr-Commit-Position: refs/heads/master@{#450726}
> Committed:
https://chromium.googlesource.com/chromium/src/+/da4637b0c789f6360dacdea216dd...

TBR=kylechar@chromium.org,fwang@igalia.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=666958

Review-Url: https://codereview.chromium.org/2694413003
Cr-Commit-Position: refs/heads/master@{#450742}
Committed:
https://chromium.googlesource.com/chromium/src/+/03f2053328cb3ab19f5c5a0348cc...
==========

[commit-bot: I haz the power, 2017-02-15 18:24:23]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/03f2053328cb3ab19f5c5a0348cc...