I'm pretty sure ChromeBug (http://getfirebug.com/releases/#chromebug http://getfirebug.com/releases/#chromebug) lets you do this, though it has some trade-offs.

I'm pretty sure ChromeBug (http://getfirebug.com/releases/#chromebug http://getfirebug.com/releases/#chromebug) lets you do this, though it has some trade-offs. On one hand, it's built on top of Firebug; this adds a lot of power (chrome inspection, javascript debugging/breakpoints in the chrome). On the other, it's alpha, and not the focus of development (as far as I can tell)--it hasn't had a new release in some time.