Layout <mspace> elements.

third_party/WebKit/Source/core/layout/mathml/BUILD.gn

@@ -10,10 +10,14 @@ blink_core_sources("mathml") {
     "layout_ng_mathml_block.h",
     "layout_ng_mathml_math.cc",
     "layout_ng_mathml_math.h",
+    "layout_ng_mathml_space.cc",
+    "layout_ng_mathml_space.h",
     "ng_mathml_input_node.cc",
     "ng_mathml_input_node.h",
     "ng_mathml_math_node.cc",
     "ng_mathml_math_node.h",
+    "ng_mathml_space_node.cc",
+    "ng_mathml_space_node.h",
   ]
 
   configs += [

third_party/WebKit/Source/core/layout/mathml/layout_ng_mathml_space.cc

@@ -0,0 +1,28 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "layout_ng_mathml_space.h"
+
+#include "core/mathml/MathMLSpaceElement.h"
+
+namespace blink {
+
+LayoutNGMathMLSpace::LayoutNGMathMLSpace(MathMLSpaceElement* element)
+    : LayoutNGMathMLBlock(element) {
+  DCHECK(element);
+}
+
+void LayoutNGMathMLSpace::layoutBlock(bool relayoutChildren) {
+  ASSERT_NOT_REACHED();  // Should use LayoutNG instead
+  clearNeedsLayout();
+}
+
+NGMathMLSpaceNode* LayoutNGMathMLSpace::toNGLayoutInputNode(
+    const ComputedStyle& style) {
+  MathMLSpaceElement* spaceElement = toMathMLSpaceElement(node());
+  return new NGMathMLSpaceNode(this, spaceElement->width(),
+                               spaceElement->height(), spaceElement->depth());
+}
+
+}  // namespace blink

third_party/WebKit/Source/core/layout/mathml/layout_ng_mathml_space.h

@@ -0,0 +1,28 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef LayoutNGMathMLSpace_h
+#define LayoutNGMathMLSpace_h
+
+#include "core/layout/mathml/ng_mathml_space_node.h"
+
+#include "core/layout/LayoutBlock.h"
+#include "core/layout/mathml/layout_ng_mathml_block.h"
+
+namespace blink {
+
+class MathMLSpaceElement;
+
+class LayoutNGMathMLSpace final : public LayoutNGMathMLBlock {
+ public:
+  explicit LayoutNGMathMLSpace(MathMLSpaceElement*);
+  ~LayoutNGMathMLSpace() override = default;
+  void layoutBlock(bool relayoutChildren) override;
+  const char* name() const override { return "LayoutNGMathMLSpace"; }
+
+  NGMathMLSpaceNode* toNGLayoutInputNode(const ComputedStyle&) override;
+};
+}
+
+#endif  // LayoutNGMathMLSpace_h

third_party/WebKit/Source/core/layout/mathml/ng_mathml_space_node.cc

@@ -0,0 +1,30 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/layout/mathml/ng_mathml_space_node.h"
+
+#include "core/layout/ng/ng_fragment_builder.h"
+
+namespace blink {
+
+RefPtr<NGLayoutResult> NGMathMLSpaceNode::Layout(
+    NGConstraintSpace* constraint_space,
+    NGBreakToken* break_token) {
+  NGFragmentBuilder builder(NGPhysicalFragment::kFragmentBox, this);
+
+  // FIXME: We should use height & depth to set NGFragment's alignmentBaseline.
+  LayoutUnit blockSize = toUserUnits(m_height, LayoutUnit(0)) +
+                         toUserUnits(m_depth, LayoutUnit(0));
+
+  RefPtr<NGLayoutResult> result =
+      builder.SetBlockSize(blockSize)
+          .SetInlineSize(toUserUnits(m_width, LayoutUnit(0)))
+          .ToBoxFragment();
+
+  CopyFragmentDataToLayoutBox(*constraint_space, result.get());
+
+  return result;
+}
+
+}  // namespace blink

third_party/WebKit/Source/core/layout/mathml/ng_mathml_space_node.h

@@ -0,0 +1,43 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NGMathMLSpaceNode_h
+#define NGMathMLSpaceNode_h
+
+#include "core/layout/mathml/ng_mathml_input_node.h"
+
+#include "core/mathml/MathMLElement.h"
+
+namespace blink {
+
+// Let's assume we're a block so our parent can layout us as such, but override
+// our layout algorithm so new we layout the children using a simplified
+// algorithm for MathML.
+//
+// FIXME(emilio): This might need more care, but right now LayoutNG only does
+// Block and a simplified version of inline layout, so making it quack like a
+// block is probably ok.
+class NGMathMLSpaceNode final : public NGMathMLInputNode {
+ public:
+  explicit NGMathMLSpaceNode(LayoutObject* flow,
+                             const MathMLElement::Length& width,
+                             const MathMLElement::Length& height,
+                             const MathMLElement::Length& depth)
+      : NGMathMLInputNode(flow),
+        m_width(width),
+        m_height(height),
+        m_depth(depth) {}
+
+  RefPtr<NGLayoutResult> Layout(NGConstraintSpace* constraint_space,
+                                NGBreakToken* break_token) final;
+
+ private:
+  const MathMLElement::Length& m_width;
+  const MathMLElement::Length& m_height;
+  const MathMLElement::Length& m_depth;
+};
+
+}  // namespace blink
+
+#endif

third_party/WebKit/Source/core/mathml/BUILD.gn

@@ -10,6 +10,8 @@ blink_core_sources("mathml") {
     "MathMLElement.h",
     "MathMLMathElement.cpp",
     "MathMLMathElement.h",
+    "MathMLSpaceElement.cpp",
+    "MathMLSpaceElement.h",
     "MathMLUnknownElement.cpp",
     "MathMLUnknownElement.h",
   ]

third_party/WebKit/Source/core/mathml/MathMLSpaceElement.cpp

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2017 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "core/mathml/MathMLSpaceElement.h"
+
+#include "core/layout/mathml/layout_ng_mathml_space.h"
+
+namespace blink {
+
+using namespace MathMLNames;
+
+MathMLSpaceElement::MathMLSpaceElement(Document& doc)
+    : MathMLElement(MathMLNames::mspaceTag, doc) {}
+
+DEFINE_NODE_FACTORY(MathMLSpaceElement)
+
+void MathMLSpaceElement::parseAttribute(
+    const AttributeModificationParams& param) {
+  if (param.name == widthAttr)
+    m_width.dirty = true;
+  else if (param.name == heightAttr)
+    m_height.dirty = true;
+  else if (param.name == depthAttr)
+    m_depth.dirty = true;
+
+  MathMLElement::parseAttribute(param);
+}
+
+/*
+ * TODO(emilio): We could consider writing our custom paint code for MathML
+ * stuff, and then we'd only need to create LayoutNGNodes.
+ *
+ * But meanwhile...
+ */
+LayoutObject* MathMLSpaceElement::createLayoutObject(const ComputedStyle&) {
+  return new LayoutNGMathMLSpace(this);
+}
+
+}  // namespace blink

third_party/WebKit/Source/core/mathml/MathMLSpaceElement.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2017 The Chromium Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef MathMLMSpaceElement_h
+#define MathMLMSpaceElement_h
+
+#include "core/MathMLNames.h"
+#include "core/mathml/MathMLElement.h"
+
+namespace blink {
+
+class LayoutObject;
+class ComputedStyle;
+
+class MathMLSpaceElement final : public MathMLElement {
+ public:
+  DECLARE_NODE_FACTORY(MathMLSpaceElement);
+
+  const Length& width() {
+    return cachedMathMLLength(MathMLNames::widthAttr, m_width);
+  }
+  const Length& height() {
+    return cachedMathMLLength(MathMLNames::heightAttr, m_height);
+  }
+  const Length& depth() {
+    return cachedMathMLLength(MathMLNames::depthAttr, m_depth);
+  }
+
+ protected:
+  explicit MathMLSpaceElement(Document&);
+
+ private:
+  LayoutObject* createLayoutObject(const ComputedStyle&) override;
+  virtual void parseAttribute(const AttributeModificationParams&);
+
+  Length m_width;
+  Length m_height;
+  Length m_depth;
+};
+
+}  // namespace blink
+
+#endif  // MathMLMSpaceElement

third_party/WebKit/Source/core/mathml/MathMLTagNames.json5

@@ -18,7 +18,7 @@
     },
     {
       name: "mspace",
-      interfaceName: "MathMLElement",
+      interfaceName: "MathMLSpaceElement",
     },
     {
       name: "mi",