[mathml] Add helper methods to NGLayoutInputNode

Add helper methods to NGLayoutInputNode to test whether the
input node is MathML and to get the DOM node for the
wrapped layout object.

Bug: 6606

Change-Id: I4b12e81b2c044e9bd98479c1ab0cf8f0c7cea898
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424183
Commit-Queue: Rob Buis <rbuis@igalia.com>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809398}

third_party/blink/renderer/core/layout/ng/mathml/ng_math_layout_utils.cc

@@ -71,7 +71,7 @@ bool IsValidMathMLFraction(const NGBlockNode& node) {
 }
 
 static bool IsPrescriptDelimiter(const NGBlockNode& block_node) {
-  auto* node = block_node.GetLayoutBox()->GetNode();
+  auto* node = block_node.GetDOMNode();
   return node && IsA<MathMLElement>(node) &&
          node->HasTagName(mathml_names::kMprescriptsTag);
 }
@@ -116,7 +116,7 @@ bool IsValidMathMLScript(const NGBlockNode& node) {
 
 bool IsValidMathMLRadical(const NGBlockNode& node) {
   auto* radical =
-      DynamicTo<MathMLRadicalElement>(node.GetLayoutBox()->GetNode());
+      DynamicTo<MathMLRadicalElement>(node.GetDOMNode());
   return !radical->HasIndex() || InFlowChildCountIs(node, 2);
 }
 
@@ -201,13 +201,13 @@ bool IsUnderOverLaidOutAsSubSup(const NGBlockNode& node) {
   DCHECK(IsValidMathMLScript(node));
   if (HasDisplayStyle(node.Style()))
     return false;
-  if (!node.IsBlock() || !node.GetLayoutBox()->IsMathML())
+  if (!node.IsBlock() || !node.IsMathML())
     return false;
   auto base = To<NGBlockNode>(FirstChildInFlow(node));
   // TODO(crbug.com/1124298)):
   // https://mathml-refresh.github.io/mathml-core/#embellished-operators
   if (auto* element =
-          DynamicTo<MathMLOperatorElement>(base.GetLayoutBox()->GetNode())) {
+          DynamicTo<MathMLOperatorElement>(base.GetDOMNode())) {
     return element->HasBooleanProperty(MathMLOperatorElement::kMovableLimits);
   }
   return false;

third_party/blink/renderer/core/layout/ng/mathml/ng_math_row_layout_algorithm.cc

@@ -30,7 +30,7 @@ static void DetermineOperatorSpacing(const NGLayoutInputNode& node,
                                      LayoutUnit* lspace,
                                      LayoutUnit* rspace) {
   auto* core_operator =
-      DynamicTo<MathMLOperatorElement>(node.GetLayoutBox()->GetNode());
+      DynamicTo<MathMLOperatorElement>(node.GetDOMNode());
   if (core_operator) {
     // TODO(crbug.com/1124298): Implement embellished operators.
     LayoutUnit leading_space(core_operator->DefaultLeadingSpace() *

third_party/blink/renderer/core/layout/ng/mathml/ng_math_scripts_layout_algorithm.cc

@@ -16,7 +16,7 @@ namespace {
 using MathConstants = OpenTypeMathSupport::MathConstants;
 
 static bool IsPrescriptDelimiter(const NGBlockNode& blockNode) {
-  auto* node = blockNode.GetLayoutBox()->GetNode();
+  auto* node = blockNode.GetDOMNode();
   return node && IsA<MathMLElement>(node) &&
          node->HasTagName(mathml_names::kMprescriptsTag);
 }

third_party/blink/renderer/core/layout/ng/mathml/ng_math_under_over_layout_algorithm.cc

@@ -124,7 +124,7 @@ UnderOverVerticalParameters GetUnderOverVerticalParameters(
 // https://mathml-refresh.github.io/mathml-core/#underscripts-and-overscripts-munder-mover-munderover
 bool HasAccent(const NGBlockNode& node, bool accent_under) {
   DCHECK(node);
-  auto* underover = To<MathMLUnderOverElement>(node.GetLayoutBox()->GetNode());
+  auto* underover = To<MathMLUnderOverElement>(node.GetDOMNode());
   auto script_type = underover->GetScriptType();
   DCHECK(script_type == MathScriptType::kUnderOver ||
          (accent_under && script_type == MathScriptType::kUnder) ||
@@ -203,7 +203,7 @@ scoped_refptr<const NGLayoutResult> NGMathUnderOverLayoutAlgorithm::Layout() {
   bool is_base_large_operator = false;
   bool is_base_stretchy_in_inline_axis = false;
   if (auto* core_operator =
-          DynamicTo<MathMLOperatorElement>(base.GetLayoutBox()->GetNode())) {
+          DynamicTo<MathMLOperatorElement>(base.GetDOMNode())) {
     // TODO(crbug.com/1124298): Implement embellished operators.
     is_base_large_operator =
         core_operator->HasBooleanProperty(MathMLOperatorElement::kLargeOp);

third_party/blink/renderer/core/layout/ng/ng_block_node.cc

@@ -391,7 +391,7 @@ bool CanUseCachedIntrinsicInlineSizes(const MinMaxSizesInput& input,
 }
 
 bool IsContentMinimumInlineSizeZero(const NGBlockNode& block_node) {
-  const auto* node = block_node.GetLayoutBox()->GetNode();
+  const auto* node = block_node.GetDOMNode();
   const auto* marquee_element = DynamicTo<HTMLMarqueeElement>(node);
   if (marquee_element && marquee_element->IsHorizontal())
     return true;
@@ -1391,13 +1391,13 @@ bool NGBlockNode::IsCustomLayoutLoaded() const {
 }
 
 MathScriptType NGBlockNode::ScriptType() const {
-  DCHECK(IsA<MathMLScriptsElement>(GetLayoutBox()->GetNode()));
-  return To<MathMLScriptsElement>(GetLayoutBox()->GetNode())->GetScriptType();
+  DCHECK(IsA<MathMLScriptsElement>(GetDOMNode()));
+  return To<MathMLScriptsElement>(GetDOMNode())->GetScriptType();
 }
 
 bool NGBlockNode::HasIndex() const {
-  DCHECK(IsA<MathMLRadicalElement>(GetLayoutBox()->GetNode()));
-  return To<MathMLRadicalElement>(GetLayoutBox()->GetNode())->HasIndex();
+  DCHECK(IsA<MathMLRadicalElement>(GetDOMNode()));
+  return To<MathMLRadicalElement>(GetDOMNode())->HasIndex();
 }
 
 scoped_refptr<const NGLayoutResult> NGBlockNode::LayoutAtomicInline(

third_party/blink/renderer/core/layout/ng/ng_layout_input_node.h

@@ -157,6 +157,7 @@ class CORE_EXPORT NGLayoutInputNode {
   wtf_size_t TableCellRowspan() const;
 
   bool IsMathRoot() const { return box_->IsMathMLRoot(); }
+  bool IsMathML() const { return box_->IsMathML(); }
 
   bool IsAnonymousBlock() const { return box_->IsAnonymousBlock(); }
 
@@ -210,6 +211,8 @@ class CORE_EXPORT NGLayoutInputNode {
 
   Document& GetDocument() const { return box_->GetDocument(); }
 
+  Node* GetDOMNode() const { return box_->GetNode(); }
+
   PhysicalSize InitialContainingBlockSize() const;
 
   // Returns the LayoutObject which is associated with this node.

third_party/blink/renderer/core/layout/ng/table/ng_table_layout_algorithm_types.cc

@@ -155,7 +155,7 @@ NGTableTypes::CellInlineConstraint NGTableTypes::CreateCellInlineConstraint(
     // Has not worked in Legacy, might be pulled out.
     if (css_inline_size && node.GetDocument().InQuirksMode()) {
       bool has_nowrap_attribute =
-          !To<Element>(node.GetLayoutBox()->GetNode())
+          !To<Element>(node.GetDOMNode())
                ->FastGetAttribute(html_names::kNowrapAttr)
                .IsNull();
       if (has_nowrap_attribute && node.Style().AutoWrap()) {
@@ -210,7 +210,7 @@ NGTableTypes::Section NGTableTypes::CreateSection(
   if (section_css_block_size.IsPercent())
     percent = section_css_block_size.Percent();
   bool is_tbody =
-      section.GetLayoutBox()->GetNode()->HasTagName(html_names::kTbodyTag);
+      section.GetDOMNode()->HasTagName(html_names::kTbodyTag);
   return Section{start_row,
                  rows,
                  block_size,