Eliminate a timed wait from ExportedObject::HandleMessage().

Eliminate a timed wait from ExportedObject::HandleMessage().

Previouslly, we blocked in D-Bus thread until the method call is handled
in the UI thread. Turned out this was a bad idea, and caused a crash when
the UI thread is hanging (crosbug.com/21341).

This patch will eliminate the timed wait and incoming methods will be handled
completely asynchronously.

BUG=chromium-os:21341
TEST=run dbus_unittests under valgrind


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=104497

[satorux1, 2011-10-06 17:56:02]

I think this is a good one. :)

[stevenjb, 2011-10-06 21:56:12]

Agreed.
LGTM

[commit-bot: I haz the power, 2011-10-07 06:12:32]

CQ is trying the patch. Follow status at
https://chromium-status.appspot.com/cq/satorux@chromium.org/8175009/1

[commit-bot: I haz the power, 2011-10-07 07:14:07]

The commit queue went berserk retrying too often for a
seemingly flaky test. Builder is linux_rel, revision is 104441, job name
was 8175009-1 (previous was lost) (previous was lost) (previous was lost)
(previous was lost).

[commit-bot: I haz the power, 2011-10-07 15:01:32]

CQ is trying the patch. Follow status at
https://chromium-status.appspot.com/cq/satorux@chromium.org/8175009/1

[commit-bot: I haz the power, 2011-10-07 16:26:32]

Change committed as 104497