layout: Cache IndependentNonReplacedContents::layout() (#36082)

This replaces `IndependentLayout` with `CacheableLayoutResult` and
stores it in `LayoutBoxBase` so it can be reused when we need to lay out
a box multiple times.

This is a generalization of the caching that we had for flexbox, which
is now removed in favor of the new one.

With this, the number of runs per second in the Chromium perf test
`flexbox-deeply-nested-column-flow.html` are multiplied by 3.

Signed-off-by: Oriol Brufau <obrufau@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>

components/layout_2020/positioned.rs

@@ -41,6 +41,7 @@ pub(crate) struct AbsolutelyPositionedBox {
     pub context: IndependentFormattingContext,
 }
 
+#[derive(Clone)]
 pub(crate) struct PositioningContext {
     for_nearest_positioned_ancestor: Option<Vec<HoistedAbsolutelyPositionedBox>>,
 
@@ -50,6 +51,7 @@ pub(crate) struct PositioningContext {
     for_nearest_containing_block_for_all_descendants: Vec<HoistedAbsolutelyPositionedBox>,
 }
 
+#[derive(Clone)]
 pub(crate) struct HoistedAbsolutelyPositionedBox {
     absolutely_positioned_box: ArcRefCell<AbsolutelyPositionedBox>,
 
@@ -299,7 +301,7 @@ impl PositioningContext {
             .push(box_)
     }
 
-    fn is_empty(&self) -> bool {
+    pub(crate) fn is_empty(&self) -> bool {
         self.for_nearest_containing_block_for_all_descendants
             .is_empty() &&
             self.for_nearest_positioned_ancestor
@@ -627,6 +629,7 @@ impl HoistedAbsolutelyPositionedBox {
                         &mut positioning_context,
                         &containing_block_for_children,
                         containing_block,
+                        false, /* depends_on_block_constraints */
                     );
 
                     let inline_size = if let Some(inline_size) =