Fix accessability for web notification tray.

Fix accessability for web notification tray.

This makes the system tray the first child so that it is the first tray focused when the status area widget is selected via accessibility.

This depends on http://codereview.chromium.org/10823350/

BUG=142506
For ash/ash_strings.grd:
TBR=sky@chromium.org

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=152135
Reverted: https://chromiumcodereview.appspot.com/10832389


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=152487

[stevenjb, 2012-08-16 17:09:46]

Relatively small CL now. Ready for review.

[sadrul, 2012-08-17 01:20:50]

LGTM

[commit-bot: I haz the power, 2012-08-17 16:33:38]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/stevenjb@chromium.org/10825389/1

[commit-bot: I haz the power, 2012-08-17 16:33:46]

Presubmit check for 10825389-1 failed and returned exit status 1.


Running presubmit commit checks ...

** Presubmit ERRORS **
Missing LGTM from an OWNER for files in these directories:
    ash

Presubmit checks took 1.2s to calculate.

[commit-bot: I haz the power, 2012-08-17 16:34:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/stevenjb@chromium.org/10825389/1

[commit-bot: I haz the power, 2012-08-17 19:41:42]

Change committed as 152135

[commit-bot: I haz the power, 2012-08-21 00:53:02]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/stevenjb@chromium.org/10825389/8002

[commit-bot: I haz the power, 2012-08-21 02:31:54]

Change committed as 152487