[whatwg] Fixing activeElement spec to match IE

[Erik Arvidsson]

Currently, the spec[1] says:

  "The activeElement attribute on HTMLDocument objects must return the
element in the document that is focused. If no element in the Document
is focused, this must return the body element."

This does not fully match IE, or is underspecified. If the document
has frames in it and a frame contains the focused element, the
activeElement of the HTMLDocument should return the frame element
which contains the focus.

I have a patch for WebKit [2] to match IE's behavior as described above.

[1] http://dev.w3.org/html5/spec/Overview.html#document-level-focus-apis
[2] https://bugs.webkit.org/show_bug.cgi?id=49509

erik