UI doesn't appear on site with frames

[machawk1]

e.g., http://web.archive.org/web/19990125092824/http://www-pm.larc.nasa.gov/

[machawk1]

Since the move to injection via shadow DOM, the new DOM elements never appear to be generated/displayed, causing an exception. This is because the injection code relies on the HTML body tag existing, which it may not if a page is solely made by of frames (frameset in its place).

[machawk1]

mink.js, where this needs to be detected, only has access to the background page DOM, not the content script. A countFrames() message needs to be passed to content.js to retrieve this value then set the changed functionality hook accordingly. Relevant-not-relevant to Scripts in a Frame, @jbrunelle. ;)