Comment 20 for bug 513133

quick update:

with my most recent packaging, chromium detects the default browser using:
/usr/lib/chromium-browser/xdg-settings check default-web-browser chromium-browser.desktop

it still says "no" even if Chromium is default in the Gnome Preferred Web Browser.
If you ask Chromium to make it default, now it works as expected.

The reason xdg-settings fails the 1st is that even if the gconf keys are correct, it makes one more test
(xdg-mime query default text/html) which points to firefox.

xdg-mime searches in defaults.list 1st in ~/.local/share/applications/ then in /usr/share/gnome/applications/