Editors don't keep track scrolling position after switching tabs

[sorawee]

Steps to reproduce:

1. Create two tabs
2. On the first tab, add random text (say, 1) for 100 lines.
3. Position the caret on the first line
4. Scroll to the last line.
5. Switch to the second tab and then switch back to the first tab.

Expected result:

The scrolling position is preserved. That is, I should still be viewing the area containing last line.

Actual result:

The scrolling position is at the first line (where the caret is).