Bug 275806

Transformed animated layers are painted with lower resolution while an animation is ongoing, and re-painted after the animation has ended to make sure they look their best at their resting position. When using damage tracking with an output that uses device scaling != 1x (e.g. with 2x scaling on a HiDPI screen) it is quite obvious that the repaint at the resting position after the animation is *not* producing damage rectangles because when damage is enabled the previous painted contents (with less resolution) are left in place because the location and properties of the layers have not changed. Likely we are missing some check like “if there was a paint with different resolution then damage the area” or similar.