Show and hide the "Download Diff" link depending on the interdiff state.
Review Request #5560 — Created Feb. 27, 2014 and submitted
When I made the diff revision selector operate without reloading the page, I
neglected the "Download Diff" link at the top of the page. This link should
only be shown when the page is displaying a full revision, and not when there's
an interdiff.I've changed it to use an inline style to hide the link on the first page load
if appropriate, and JS to show/hide it when the displayed revision changes.
Played around with the revision selector and watched the link show and hide
itself. Verified that if I initially loaded an interdiff, that the link was
present in the DOM to show later.
