/usr/share/applications/ubuntu-html5-ui-gallery.desktop is in ubuntu-html5-ui-toolkit-examples 0.1.2+14.04.20140404-0ubuntu2.
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 | [Desktop Entry]
Name=Ubuntu HTML5 UI Gallery
Type=Application
Exec=qmlscene /usr/share/ubuntu-html5-ui-toolkit/0.1/examples/ui-gallery/qml/main.qml
Icon=ubuntu
Terminal=false
X-Ubuntu-Touch=true
|