OK I found it!So I will answer here.
/desktop/gnome/url-handlers) didn't do anything since as of Natty the file-open functionality is handled by
gvfs-open, which doesn't use gconf settings. Rather, gvfs-open looks at the ".desktop" files bundled with each application to determine what file types can be handled.if it is not installed, run :
sudo apt-get install gvfs-bin
In all x-scheme handler urls( like irc://, xmpp://, sip://, aim://) are handled by purple-url-handler.We are going to create a desktop file for it.
gksudo gedit /usr/share/applications/purple-url-handler.desktop
& put following content in it:
Name=Purple URL Handler
Comment=URL handler forGoogle Talk, Jabber/XMPP, MSN, Yahoo and more
Now to make irc:// links open with purple-url-handler run :
xdg-mime default purple-url-handler.desktop x-scheme-handler/irc
This informator is stored in ~/.local/share/applications/mimeapps.list.
Now when you click any irc:// link in chromium for the first time, the following prompt will appear:
Select remember my choice & launch application. If you are already logged in it will open the room in pidgin.