Is it safe to auto-fill credit card numbers using Chrome?

Is it possible for breaching google chrome and take my credit card information?

Yes.

As long as Chrome can use your number for auto completion, it has to be possible for Chrome to access it. If one program on your computer can do this, another program or a least humans can do it too.

it's not stored with any type of encryption

Even with encryption, the statement above holds. Chrome would need the key, and this key has to be somewhere on your computer so that Chrome can use it.

As long as someone can physically access your computer, few things actually help. Encrypting your whole hard drive and taking the key away with you is one possibility. Downside 1: It´s a pain to insert flash drive and password each time to turn it on. Downside 2: If someone gets your computer while it is turned on, everything is futile again.

If you only want to protect against attacks form the internet, this is much better, but nonetheless there is no 100% protection. Not entering your card number (or any sensitive data) in the computer is the only reliable way.

1) Yes, it is possible to breach Google Chrome. Even with the encryption, there would be somewhere password or private key.

2) It is not secure as not using autofill, however, you do not type in the autofill your CVV code, which is needed for a successful operation with the card. You can find more about CVV here: https://www.cvvnumber.com/