[glass-]

It's entirely inconsistent with Mozilla's past actions.

You can compile Firefox source code of which 100% of it came from released Firefox versions in Mozilla's HG tree and they won't let you call that "Firefox". Part of why IceWeasel exists is Debian wanted to backport security patches from Firefox releases into an older version (eg. apply security patches from Firefox 4 to Firefox 3.5) for Debian-stable and Mozilla wouldn't let them use the name Firefox if they did that.

Therefore your claim that

> Firefox is the UI chrome and corresponding stack

doesn't match the reality of what Mozilla has done. It seems now Firefox is anything that Mozilla calls Firefox.