You can use userscript to automatically upload UserData file. It contains information owned games and DLC and your wishlist.
Firefox requires Greasemonkey.
Chrome requires Tampermonkey

Install or Update Userscript Status: Not InstalledInstalled

Manual Update

You can also manually upload your UserData file below:

Click Here. Copy all text to field above. It should like

. If Firefox displays formated data, just click "Copy".

Delete Data

Delete data uploaded by userscript or Manual Update.
While this can't be undone, you an always reinstall userscript or reupload data manually.