When review UIs are rendered into the diff viewer, the fragment template was including an "inline-actions-header" table row. In a case that in practice would never be hit, this could theoretically contain "Review" and "New Comment" buttons (like we have in the file attachment thumbnail), but those buttons had no handlers. In the more common case of a review UI that renders inline review content, the result was an ugly table row that didn't have anything in it, but took up space. Testing Done: Looked at the diff viewer with image review UIs rendered and saw that there weren't any ugly gaps.