Some WebKit clients need to know which frame in a frameset is largest for their UI decisions. They want the answer synchronously. Since UI process doesn't track frame sizes, and we want to keep it that way, it needs to track which frame is largest.
Created attachment 77938 [details] proposed patch Some potential areas of concern: - Is the algorithm what clients want? I reinvented it. - There is no strong guarantee that new data members will be cleared up when frame tree changes. As far as I can tell, WebFrame classes on both sides will not be too upset, but I can't be sure.
Comment on attachment 77938 [details] proposed patch I think the names need to indicate that it is the largest frame is in the mainFrame frameset. I am also not sure we really need to be doing this on all contentSize changes, but I don't think it matters.
Created attachment 77943 [details] patch for landing I couldn't come up with better names. The fact that these member variables are in per-page classes should hopefully serve as a hint.
Comment on attachment 77943 [details] patch for landing Clearing flags on attachment: 77943 Committed r75054: <http://trac.webkit.org/changeset/75054>
All reviewed patches have been landed. Closing bug.