Proving deleted/syncronised internet history?

Hi,
Long story short. I have some deleted internet history (Chrome on Android phone) but how can I prove the user has deleted it and what date he deleted it and another auto process hasnt deleted it? Another sub question …. how do I know the url's on his phone are not sync'd from another device?

I'm guessing there is a .DB somewhere on the phone that tracks sync'd url's? I only have a phone to work with and no other assumed devices.

I've used Ufed to get a read off the phone and have IEF at my disposal as well as SQL tools.

Thanks