Losing page scroll height upon switching diff mode in review preferences

Steps to reproduce
1) Create review and add attached patches
2) Make sure your browser window height is about 750px
3) Click on "remote_test_node.go" file
4) Click on "Prefs" and select "Side-by-side Diffs"
5) Select file "zulti_node_kill_all_and_recovery_test.go"
6) Click on "remote_test_node.go" again but this time switch diff mode to "Unified Diffs" by "Prefs" menu
7) Try to scroll down to the bottom of the file

Result
You can't see end of file

Expected
But you should