When you work on a code, you usually work on 3/4 spots at the same time. You tweak, then you go to the next part, and you tweak, then you go back to the previous part. Then you click on another tab to check something. You scroll. You then go back, etc.
Having some 'back' and 'forward' arrows like in a browser would really ease this process. Every time you click on some part of a text file, it's like when you enter a URL in the web browser: you change location, and the location get added to the history.
The history should go across tabs of course, as you usually edit several files at the same time.