Auto merge of #11850 - splav:box-shadow#11662, r=glennw

Fix PaintContext page_rect due to display list origin

Fix PaintContext page_rect due to non zero display list origin.

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- [X] These changes fix #11662 (github issue number if applicable).

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components/gfx/paint_thread.rs

@@ -684,7 +684,7 @@ impl WorkerThread {
             let mut paint_context = PaintContext {
                 draw_target: draw_target.clone(),
                 font_context: &mut self.font_context,
-                page_rect: Rect::from_untyped(&tile.page_rect),
+                page_rect: Rect::from_untyped(&tile.page_rect.translate(&paint_layer.display_list_origin)),
                 screen_rect: Rect::from_untyped(&tile.screen_rect),
                 clip_rect: None,
                 transient_clip: None,