Bug 40778

Created attachment 58997 [details] Test with run-launcher -graphics-based Attached is an example of a CSS transform that causes rendering/animation issues with GraphicsLayer/accelerated compositing (i.e. when QWebSettings::AcceleratedCompositingEnabled is true). The example shows two boxes. When you click the screen, the right box (which is initially hidden) moves to the left and transforms to opacity 1, while the left box moves to the right and transforms to opacity 0 with a slight delay (using -webkit-transition-delay). When AC is not enabled, the transforms work properly, but when it is enabled the box with the delayed animation disappears and then does not start it's transform until the other box finishes. Without the delay everything works fine with or without AC.