Make sure the Autolaunch infobar...

Make sure the Autolaunch infobar...

1) shows up on First Run of Chrome (for the right experiment brand code).
2) takes precedent over the 'Chrome is not your default browser' infobar.
3) is not shown if other infobars are present.

Also some minor cleanup:

- Renamed IsInAutoLaunchGroup to IsInAutoLaunchFieldTrial (better fit).
- Moved brand specific code to auto_launch_trial namespace (easier to find) and created meaningful function names for'em.

BUG=106801
TEST=This requires a special branded build (see instructions for http://codereview.chromium.org/8729009).
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=114974

[Finnur, 2011-12-16 16:48:50]

Care for some minor polish?

[Roger Tawa OOO till Jul 10th, 2011-12-16 20:44:31]

lgtm

http://codereview.chromium.org/8969024/diff/1/chrome/browser/auto_launch_tria...
File chrome/browser/auto_launch_trial.cc (right):

http://codereview.chromium.org/8969024/diff/1/chrome/browser/auto_launch_tria...
chrome/browser/auto_launch_trial.cc:21: bool IsInAutoLaunchFieldTrial() {
I actually think the old name was better.  Remember that the control group *is*
in the field trial; they just happen to be ones not getting the extra goodies. 
They are different from the "rest of the population" since the rest is not being
tracked with user metrics.