Fix DCHECK with force-device-scale-factor switch enabled.

Fix DCHECK with force-device-scale-factor switch enabled.

This CL fixes a DCHECK happening due to r284913. The CL changed the order
of window addition which caused window properties to update in a different
order. This is fixed by only running the DCHECKed code after the window
is parented beneath a root window.

BUG=396911
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=285833

[stevenjb, 2014-07-24 18:58:07]

->oshima@

[oshima, 2014-07-24 23:16:06]

lgtm

[calamity, 2014-07-24 23:46:41]

The CQ bit was checked by calamity@chromium.org

[commit-bot: I haz the power, 2014-07-24 23:50:37]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/calamity@chromium.org/417923003/1

[commit-bot: I haz the power, 2014-07-25 04:33:10]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  chromium_presubmit on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/chromium_presubmit/bu...)

[commit-bot: I haz the power, 2014-07-25 04:36:55]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-07-25 04:36:56]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/chromium_presubmit/bu...)

[calamity, 2014-07-25 05:36:15]

+sky for OWNERS.

[sky, 2014-07-25 16:06:55]

LGTM

[calamity, 2014-07-27 03:46:59]

The CQ bit was checked by calamity@chromium.org

[commit-bot: I haz the power, 2014-07-27 03:47:22]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/calamity@chromium.org/417923003/1

[commit-bot: I haz the power, 2014-07-27 06:37:36]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_chromium_rel on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel/...)

[commit-bot: I haz the power, 2014-07-27 11:21:18]

Change committed as 285833