We currently have to scroll all the way to the top if we want to be navigated to a

specific diff file.
I added a floating banner to the diff view that sticks to the top of the page when

the user has scrolled down on the page. On this banner, I will further add a

collapsed list of the diff files, showing only the the file that the user is currently

looking at. The user will be able to expand this list to navigate to the other files.
Screenshots and demo video: Notion

I have tested the floating banner on the dev server on review requests with multiple 

diff files.
I have started writing jasmine tests for the floating banner. This is still a WIP.

The banner has been manually tested (including responsiveness) on Chrome, Safari, and 

Firefox. Click here to see GIFs of the manual tests (running on diff revision 13). 
Further testing on other browsers are required.