We'd like to spot frames that took long to render even in cases where CPU time usage by nested events was small, so add a contour for overall frame length to frame bars in the vertical overview. This also requires better scaling logic, so that should we have any irregularly-long frames (i.e. in absence of requestAnimationFrame calls), these do not dwarf the rest of the frames -- so we now scale to no more than 3 * median_frame_length, which causes badly outlying frames to rocket into the sky (right in time for April, 12th).
Created attachment 136753 [details] screenshot (regular frames, outliers clearly seen)
Created attachment 136754 [details] screenshot (irregular -- scrolling techcrunch back and forth)
Created attachment 136756 [details] Patch
Committed r113994: <http://trac.webkit.org/changeset/113994>