Reproduction: 1. http://webstuff.nfshost.com/anim-timing/raftime.html 2. Slide delay slider to the right to add delay to each frame. Notice that when moving the slider slightly, performance becomes extremely choppy. Much choppier than it should be given the reported FPS. Also much choppier than it should be given the delay. When you slide the delay slider, it should get choppier since you are lowering frame rate. However, the choppiness should be consistent, meaning the same time interval between frames. The bug is that it is inconsistent and stutters. When this is performing correctly, it should transition smoothly to being more choppy as you move the slider to the right. The FPS should reflect the amount of choppiness you see, and the choppiness should be consistent.
Created attachment 136292 [details] Patch
Comment on attachment 136292 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=136292&action=review Looks good, but fix ChangeLog first please :) > Source/WebCore/ChangeLog:10 > + Reviewed by NOBODY (OOPS!). The reviewed by line should go between bug/title and explanation.
Created attachment 136296 [details] Patch
Comment on attachment 136296 [details] Patch Looks good.
Comment on attachment 136296 [details] Patch Clearing flags on attachment: 136296 Committed r113644: <http://trac.webkit.org/changeset/113644>
All reviewed patches have been landed. Closing bug.