
If a user in diff view changes the diff range to one that no longer includes the file that they are on, the Prev/Next links are grayed out and they are forced to return to the change view to navigate the diff. This change sets Next to direct to the first file in the list and Prev to point to the last file in the list. Bug: Issue 4932 Change-Id: Ifb460c9721bfafbc19afa68253402b9dcd2f2c3e