don't init ash window unless in ash mode

Don't init ash window unless in ash mode

retry of https://codereview.chromium.org/11187005/

R=ben@chromium.org
BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=162365

[scottmg, 2012-10-16 18:01:43]

(previous attempt broke on gtk, bleh)

[Ben Goodger (Google), 2012-10-16 18:08:24]

lgtm

[commit-bot: I haz the power, 2012-10-16 21:45:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/scottmg@chromium.org/11192007/1

[commit-bot: I haz the power, 2012-10-17 11:19:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/scottmg@chromium.org/11192007/1

[commit-bot: I haz the power, 2012-10-17 12:43:51]

Change committed as 162365