Firstly, I'd imagine China is pleased to see the US becoming weaker on the world stage. At least, in the long term.
But, secondly, China has its own problems at home right now and the US, which is about to have a lot less spending power, is a huge customer of China's. Xi is likely going to take a "wait and see" approach and assess the shifting situation. Any amount of China and Russia getting close would likely be purely from an "enemy of my enemy is my friend" perspective and I doubt it would last. None of the major powers mingle for very long before stepping on each other's feet.
Xi isn't stupid. I'm sure he's well aware that Putin would betray him in an instant for power and that Trump is both a Russian asset and a moron.
Fixed.