/usr/share/applications/lxde-x-www-browser.desktop is in lxpanel 0.6.1-0ubuntu3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 | [Desktop Entry]
Name=Web Browser
Name[pt_BR]=Navegador web
Name[zh_TW]=瀏覽器
GenericName=X Web Browser
GenericName[pt_BR]=Navegador web gráfico
GenericName[zh_TW]=網頁瀏覽器
Exec=/usr/bin/x-www-browser %u
Terminal=false
Type=Application
Categories=GTK;WebBrowser;Network
Icon=web-browser
NoDisplay=true
|