1 files changed, 20 insertions, 26 deletions

diff --git a/layout/base/nsCSSFrameConstructor.cpp b/layout/base/nsCSSFrameConstructor.cpp
index 149f2f24bf..ba43eb70b9 100644
--- a/layout/base/nsCSSFrameConstructor.cpp
+++ b/layout/base/nsCSSFrameConstructor.cpp
@@ -1537,12 +1537,11 @@ already_AddRefed<nsIContent> nsCSSFrameConstructor::CreateGenConTextNode(
 
 void nsCSSFrameConstructor::CreateGeneratedContent(
     nsFrameConstructorState& aState, Element& aOriginatingElement,
-    ComputedStyle& aPseudoStyle, uint32_t aContentIndex,
-    const FunctionRef<void(nsIContent*)> aAddChild) {
+    ComputedStyle& aPseudoStyle, const StyleContentItem& aItem,
+    size_t aContentIndex, const FunctionRef<void(nsIContent*)> aAddChild) {
   using Type = StyleContentItem::Tag;
   // Get the content value
-  const auto& item = aPseudoStyle.StyleContent()->ContentAt(aContentIndex);
-  const Type type = item.tag;
+  const Type type = aItem.tag;
 
   switch (type) {
     case Type::Image: {
@@ -1552,7 +1551,7 @@ void nsCSSFrameConstructor::CreateGeneratedContent(
     }
 
     case Type::String: {
-      const auto string = item.AsString().AsString();
+      const auto string = aItem.AsString().AsString();
       if (string.IsEmpty()) {
         return;
       }
@@ -1563,7 +1562,7 @@ void nsCSSFrameConstructor::CreateGeneratedContent(
     }
 
     case Type::Attr: {
-      const auto& attr = item.AsAttr();
+      const auto& attr = aItem.AsAttr();
       RefPtr<nsAtom> attrName = attr.attribute.AsAtom();
       int32_t attrNameSpace = kNameSpaceID_None;
       RefPtr<nsAtom> ns = attr.namespace_url.AsAtom();
@@ -1592,11 +1591,11 @@ void nsCSSFrameConstructor::CreateGeneratedContent(
       CounterStylePtr ptr;
       nsString separator;
       if (type == Type::Counter) {
-        auto& counter = item.AsCounter();
+        auto& counter = aItem.AsCounter();
         name = counter._0.AsAtom();
         ptr = CounterStylePtr::FromStyle(counter._1);
       } else {
-        auto& counters = item.AsCounters();
+        auto& counters = aItem.AsCounters();
         name = counters._0.AsAtom();
         CopyUTF8toUTF16(counters._1.AsString(), separator);
         ptr = CounterStylePtr::FromStyle(counters._2);
@@ -1947,13 +1946,14 @@ void nsCSSFrameConstructor::CreateGeneratedContentItem(
       mPresShell->StyleSet()->StyleNewSubtree(childElement);
     }
   };
-  const uint32_t contentCount = pseudoStyle->StyleContent()->ContentCount();
-  for (uint32_t contentIndex = 0; contentIndex < contentCount; contentIndex++) {
-    CreateGeneratedContent(aState, aOriginatingElement, *pseudoStyle,
-                           contentIndex, AppendChild);
+  auto items = pseudoStyle->StyleContent()->NonAltContentItems();
+  size_t index = 0;
+  for (const auto& item : items) {
+    CreateGeneratedContent(aState, aOriginatingElement, *pseudoStyle, item,
+                           index++, AppendChild);
   }
   // If a ::marker has no 'content' then generate it from its 'list-style-*'.
-  if (contentCount == 0 && aPseudoElement == PseudoStyleType::marker) {
+  if (index == 0 && aPseudoElement == PseudoStyleType::marker) {
     CreateGeneratedContentFromListStyle(aState, aOriginatingElement,
                                         *pseudoStyle, AppendChild);
   }
@@ -4985,9 +4985,8 @@ nsCSSFrameConstructor::FindSVGData(const Element& aElement,
   return data;
 }
 
-void nsCSSFrameConstructor::InsertPageBreakItem(
-    nsIContent* aContent, FrameConstructionItemList& aItems,
-    InsertPageBreakLocation location) {
+void nsCSSFrameConstructor::AppendPageBreakItem(
+    nsIContent* aContent, FrameConstructionItemList& aItems) {
   RefPtr<ComputedStyle> pseudoStyle =
       mPresShell->StyleSet()->ResolveNonInheritingAnonymousBoxStyle(
           PseudoStyleType::pageBreak);
@@ -4997,13 +4996,8 @@ void nsCSSFrameConstructor::InsertPageBreakItem(
 
   static constexpr FrameConstructionData sPageBreakData(NS_NewPageBreakFrame,
                                                         FCDATA_SKIP_FRAMESET);
-  if (location == InsertPageBreakLocation::eBefore) {
-    aItems.PrependItem(this, &sPageBreakData, aContent, pseudoStyle.forget(),
-                       true);
-  } else {
-    aItems.AppendItem(this, &sPageBreakData, aContent, pseudoStyle.forget(),
-                      true);
-  }
+  aItems.AppendItem(this, &sPageBreakData, aContent, pseudoStyle.forget(),
+                    true);
 }
 
 bool nsCSSFrameConstructor::ShouldCreateItemsForChild(
@@ -5289,7 +5283,7 @@ void nsCSSFrameConstructor::AddFrameConstructionItemsInternal(
       aFlags.contains(ItemFlag::AllowPageBreak) &&
       aState.mPresContext->IsPaginated() &&
       !display.IsAbsolutelyPositionedStyle() &&
-      !(aParentFrame && aParentFrame->IsGridContainerFrame()) &&
+      !(aParentFrame && aParentFrame->IsFlexOrGridContainer()) &&
       !(bits & FCDATA_IS_TABLE_PART) && !(bits & FCDATA_IS_SVG_TEXT);
   if (canHavePageBreak && display.BreakBefore()) {
     AppendPageBreakItem(aContent, aItems);
@@ -6012,7 +6006,7 @@ nsIFrame* nsCSSFrameConstructor::GetInsertionPrevSibling(
 
   // Find the frame that precedes the insertion point.
   FlattenedChildIterator iter(aInsertion->mContainer);
-  if (iter.ShadowDOMInvolved() || !aChild->IsRootOfNativeAnonymousSubtree()) {
+  if (!aChild->IsRootOfNativeAnonymousSubtree()) {
     // The check for IsRootOfNativeAnonymousSubtree() is because editor is
     // severely broken and calls us directly for native anonymous
     // nodes that it creates.
@@ -8390,7 +8384,7 @@ void nsCSSFrameConstructor::RecreateFramesForContent(
   }
 
   // TODO(emilio): We technically can find the right insertion point nowadays
-  // using StyleChildrenIterator rather than FlattenedTreeIterator. But we'd
+  // using StyleChildrenIterator rather than FlattenedChildIterator. But we'd
   // need to tweak the setup to insert into replaced elements to filter which
   // anonymous roots can be allowed, and which can't.
   //