Why sign in to Chrome?
When you’re signed in to Chrome on different devices, you can choose what information will sync across them — such as your apps, bookmarks, history, and extensions. You get the same experience everywhere.
If you are signed into Chrome you should see your account icon, or letter on the top right of your browser. Please note this is different than being signed into GMail. See image below.
If you are signed in you should see something like this.
If you see something that says “Turn on Sync” go ahead and click that and then “Link Data”
For more information see the following