Here are a couple things you can try to see if those buttons will reappear in Chrome for you:
- Clear your browser cache and cookies. This is usually a good thing to try when a browser acts up.
- Extensions and add-ons can cause issues like this. Try turning them all off and see if the buttons work then. If they do, you could try returning the extensions one-by-one to try to identify which caused the issue.
- Occasionally, virus protection software can cause this so that's something else to check.
I hope one of these helps!