Shared components used by Firefox and other Mozilla software, including handling of Web content; Gecko, HTML, CSS, layout, DOM, scripts, images, networking, etc. Issues with web page layout probably go here, while Firefox user interface issues belong in the Firefox product. (More info)
Created attachment 609753[details][diff][review]
Reverse ImageLayer ordering
When we have multiple ColorLayers within a single container, their order is reversed every paint.
I believe this is because we process ThebesLayers in a stack, so we should be retrieving the ColorLayers (and ImageLayers) in reverse order.
Created attachment 618538[details][diff][review]
Attach ImageLayers to the ThebesLayer it replaces
Turns out that the original approach didn't actually work. The ordering isn't consistent at all, and reversing the order broke as many tests as it fixed.