Thingiverse is a service which offers ready-drawn shapes and figures. The best thing is they are all CC-licensed. This is what I was looking for: http://www.thingiverse.com/thing:601316
Before the actual printing I wanted to view the case on Chromebook. Two extensions were needed and are found in Chrome Web Store:
- Click to open 3D
Next, stl-files were downloaded from Thingiverse. Once .stl-file was saved it opened automatically.
Tip: if .stl-file doesn't open automatically, right-click it on the web page and choose "Click to open 3D" and "Open in 3DView".
Install 3DView extension
Install Click to open 3D extension
This is the case in this case ;P!