Comment 77 for bug 125970

Alright, not only is there a significant rise in CPU usage [still], there is
most likely a memory leak along with it. If I recall correctly, multiple tabs
or subsequent viewings of pages such as bungie.net have an after-effect of
larger memory usage (and commit charge? it doesn't seem to use the memory it
creates, hinting at a leak). I'd recommend somebody make some memory dumps of
Firefox for scrolling on a normal page (like this one) and ones for pages with
massive amounts of overhead-inducing elements (such as bungie.net).

Also, if anyone could test this using a debug version of FF (enable/create the
debugs for any possible pages that include the code that may be inducing this)
and check back with us.

We should also try to find any other programs that improve or lag the
performance while doing so. This may seem like a bit of work to do (it is if
you're not used to debugging things...), but the fact that we haven't found what
is actually causing this bug yet after _almost_2_years_ calls for some major
hacking.

Primary areas to check: anything to do with page drawing, including the XUL bits
and CSS-related bits. Also, check the JavaScript core pages that include the
functions used to simulate position-fixed scrolling and the frameset-related
core bits as these two methods of pseudo position-fixed elements appear to work
in a more orderly and optimized manner.

~Matt

Also, would Mr. McCormick please add an alias to this bug, maybe
"position-fixed"? Thanks.