[Mac] Remove a panel from stack window bounds update list when it is being removed

[Mac] Remove a panel from stack window bounds update list when it is being removed

The crash in the bug seems to occur when 2 stacked panels are being removed
in a very short peirod of time. When 1st panel is being removed, other stacked
panels could be queued for update. If 2nd panel, that is in this update list,
is then removed, it should be removed from the update list.

This only occurs on Mac. Windows does not have the problem due to the similar
logic. Linux GTK does not either due to that the update will be performed
immediately.

BUG=336582
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=247648

[Dmitry Titov, 2014-01-29 01:12:56]

lgtm after fixing compile issue.

[commit-bot: I haz the power, 2014-01-29 01:56:02]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jianli@chromium.org/143453008/20001

[commit-bot: I haz the power, 2014-01-29 04:39:48]

Retried try job too often on linux_rel for step(s) check_deps
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_rel&...

[commit-bot: I haz the power, 2014-01-29 05:33:17]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jianli@chromium.org/143453008/20001

[commit-bot: I haz the power, 2014-01-29 06:30:06]

Change committed as 247648