cashew: don't invoke D-Bus methods from within a D-Bus handler

cashew: don't invoke D-Bus methods from within a D-Bus handler

Call D-Bus methods from main loop to avoid deadlock (see issue 8486)
Set D-Bus connection timeout to 1 sec instead of using 25 sec default
Retry failed or timed out D-Bus calls

BUG=chromium-os:8516
TEST=Manual testing on device, with flimflam running and not running.

Change-Id: I27de7b539ceacc0471e89f595154fdb04fd74e5a

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=6b01cf4

[Vince Laviano, 2010-11-03 03:10:34]

Here's a first cut at the D-Bus patch.

The goals here are:

1) Don't call D-Bus methods directly from D-Bus handlers.  Instead schedule them
to be called later from the main loop. Otherwise, we're open to deadlocks.
2) Reduce the D-Bus connection timeout. The default is 25 secs.
3) Retry D-Bus calls if they fail (e.g., if flimflam is not running)

I'm not happy with the duplication across ServiceManager, Service, and Device. I
think that I should probably factor it all into a Timer class.

[Jason Glasgow, 2010-11-03 16:45:23]

LGTM with the following caveat: Yes, there is code duplication.  Yes you should
implement a timer class.  If this is tested and works though, I would favor
getting this implementation in for R9, and then refactoring during R9.x.

[Vince Laviano, 2010-11-03 18:33:11]

Ok. I've filed issue 8654 to track the refactoring work.