Use WS_POPUP for ash_unittests

Use WS_POPUP for ash_unittests
- Layout test windows starting from (1,1) and move
  mouse to (0,0) so that they don't overlap unless
  test moves the cursor.
- Enabled disabled tests.
- RootWindowHostWin::SetBounds should move the window
  and call OnHostResized when the scale factor has changed.

This also seems to fix the desktop size limitation issue (148691)
probably because a popup window can be larger than the desktop size.

BUG=150986, 157817, 141577, 148691
TEST=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=170621

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=170673

[Ben Goodger (Google), 2012-11-30 21:12:58]

lgtm

[commit-bot: I haz the power, 2012-11-30 21:28:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11428066/7004

[commit-bot: I haz the power, 2012-11-30 21:47:12]

Retried try job too often on win_aura for step(s) aura_unittests,
content_browsertests, content_unittests, views_unittests

[commit-bot: I haz the power, 2012-11-30 21:58:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11428066/7004

[commit-bot: I haz the power, 2012-12-01 01:48:47]

Change committed as 170621

[commit-bot: I haz the power, 2012-12-01 08:12:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11428066/14017

[commit-bot: I haz the power, 2012-12-01 12:10:16]

Retried try job too often on win_rel for step(s) browser_tests

[commit-bot: I haz the power, 2012-12-01 15:54:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11428066/14017

[commit-bot: I haz the power, 2012-12-01 19:45:00]

Change committed as 170673