chromium 24.0.1312.52: add launch helper and .desktop file

The .desktop file is from the Fedora chrome RPM, the script is a custom one.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
chromium: fix icon location in google-chrome.desktop

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>