Bug 1266131 part 1 - [css-grid] 'order' doesn't apply to grid-aligned abs.pos. descendants (anymore). r=dholbert

layout/generic/nsGridContainerFrame.cpp

@@ -5213,15 +5213,6 @@ nsGridContainerFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
   // Our children are all grid-level boxes, which behave the same as
   // inline-blocks in painting, so their borders/backgrounds all go on
   // the BlockBorderBackgrounds list.
-  // Also, we capture positioned descendants so we can sort them by
-  // CSS 'order'.
-  nsDisplayList positionedDescendants;
-  nsDisplayListSet childLists(aLists.BlockBorderBackgrounds(),
-                              aLists.BlockBorderBackgrounds(),
-                              aLists.Floats(),
-                              aLists.Content(),
-                              &positionedDescendants,
-                              aLists.Outlines());
   typedef GridItemCSSOrderIterator::OrderState OrderState;
   OrderState order = HasAnyStateBits(NS_STATE_GRID_NORMAL_FLOW_CHILDREN_IN_CSS_ORDER)
                        ? OrderState::eKnownOrdered
@@ -5230,11 +5221,9 @@ nsGridContainerFrame::BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 GridItemCSSOrderIterator::eIncludeAll, order);
   for (; !iter.AtEnd(); iter.Next()) {
     nsIFrame* child = *iter;
-    BuildDisplayListForChild(aBuilder, child, aDirtyRect, childLists,
+    BuildDisplayListForChild(aBuilder, child, aDirtyRect, aLists,
                              ::GetDisplayFlagsForGridItem(child));
   }
-  positionedDescendants.SortByCSSOrder();
-  aLists.PositionedDescendants()->AppendToTop(&positionedDescendants);
 }
 
 bool

layout/reftests/css-grid/reftest.list

@@ -32,7 +32,7 @@ fails == grid-whitespace-handling-1b.xhtml grid-whitespace-handling-1-ref.xhtml
 == grid-abspos-items-013.html grid-abspos-items-013-ref.html
 == grid-abspos-items-014.html grid-abspos-items-014-ref.html
 == grid-abspos-items-015.html grid-abspos-items-015-ref.html
-== grid-order-abspos-items-001.html grid-order-abspos-items-001-ref.html
+!= grid-order-abspos-items-001.html grid-order-abspos-items-001-ref.html
 == grid-order-placement-auto-001.html grid-order-placement-auto-001-ref.html
 fuzzy-if(skiaContent,1,200) == grid-order-placement-definite-001.html grid-order-placement-definite-001-ref.html
 skip-if(Android) == grid-placement-definite-implicit-001.html grid-placement-definite-implicit-001-ref.html