Incorrect scroll position when switching tabs while still scrolling

[wtmoose]

Steps:

1. Scroll to collapse the header
2. Scroll back up such that the scroll will end up at zero content offset and the header will be fully expanded
3. Switch tabs before the header start to expand
4. Switch back to the original tab

Expected: scroll position is sync with the current collapsed state of the header
Actual: scroll is at zero offset while the header remains collapsed, revealing the spacer row