As long as you are using Chrome for Android Beta on your phone or tablet, you can seamlessly pick up web browsing where you left off on your desktop. Even the back and forward buttons will work from machine to machine. Tab sync requires users, like other Sync features (such as bookmarks, apps, extensions, history, and themes), to be signed in to a Google account.
Google, however, said that not all Chrome users will be seeing the tab sync immediately. Instead, Google will pushing out tab sync "gradually over the coming weeks."