The "Change Diff" buttons lose state when changing the diff on a file.

Steps to Reproduce:

1. Go to an Open Review of which you are the Author
2. Go to the Review Tab (1.jpg)
3. Click "Show Choose Diff Buttons" (2.jpg)
4. Click "Change Diff" (3.jpg)
5. Click "Update" (4.jpg) -> Notice that the file that has been updated no longer has the "Change Diff" button while the rest do
6. Click "Hide Choose Diff Buttons" -> Notice that the changed file now has the button while the rest do not

After these steps, you can repeatedly click the Hide/Show Change Diff Buttons to see the problem.