Motorola Defy does not sync to GMail
So it turns out that there is no other way than to do it manually, and it is not difficult at all :)


Get MyPhoneExplorer (I am sure you can do it using the Phone Portal too, but MyPhoneExplorer is just SO convenient :)
Go to the Contact tab, right click on any contact, click on Export/Import, Export all contacts, and select the csv format
Check that the CSV file is OK opening it in Excel for example
Open GMail, go to the Contacts link and click on Import, select the CSV file and import
Now return to the phone explorer, and delete all your contacts
Click on android's Settings - Accounts, click on the GMail account and click on synchronize contacts. All your contacts are restored to your phone, but now they are linked in GMail.