Initial plumbing for LayoutNG Grid

This change introduces two new classes that will be used for CSS Grid
in LayoutNG, as well as the runtime flag "LayoutNGGrid" that enables
CSS Grid support in LayoutNG.

This is not at all functional yet but will allow for the subsequent
changes to focus on the implementation instead of boilerplate.

Bug: 1045599
Change-Id: I04fb4455761b1f66cf567440fc5298a39230cbbc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042056Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Kurt Catti-Schmidt <kschmi@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#756274}

third_party/blink/renderer/core/layout/BUILD.gn

@@ -396,6 +396,8 @@ blink_core_sources("layout") {
     "ng/layout_ng_fieldset.h",
     "ng/layout_ng_flexible_box.cc",
     "ng/layout_ng_flexible_box.h",
+    "ng/layout_ng_grid.cc",
+    "ng/layout_ng_grid.h",
     "ng/layout_ng_mixin.cc",
     "ng/layout_ng_mixin.h",
     "ng/layout_ng_progress.cc",
@@ -471,6 +473,8 @@ blink_core_sources("layout") {
     "ng/ng_fragment_child_iterator.h",
     "ng/ng_fragmentation_utils.cc",
     "ng/ng_fragmentation_utils.h",
+    "ng/ng_grid_layout_algorithm.cc",
+    "ng/ng_grid_layout_algorithm.h",
     "ng/ng_ink_overflow.cc",
     "ng/ng_ink_overflow.h",
     "ng/ng_layout_algorithm.h",

third_party/blink/renderer/core/layout/layout_object.cc

@@ -278,7 +278,7 @@ LayoutObject* LayoutObject::CreateObject(Element* element,
     case EDisplay::kGrid:
     case EDisplay::kInlineGrid:
       UseCounter::Count(element->GetDocument(), WebFeature::kCSSGridLayout);
-      return new LayoutGrid(element);
+      return LayoutObjectFactory::CreateGrid(*element, style, legacy);
     case EDisplay::kLayoutCustom:
     case EDisplay::kInlineLayoutCustom:
       DCHECK(RuntimeEnabledFeatures::LayoutNGEnabled());

third_party/blink/renderer/core/layout/layout_object.h

@@ -2553,6 +2553,7 @@ class CORE_EXPORT LayoutObject : public ImageResourceObserver,
     kLayoutObjectNGBlockFlow,
     kLayoutObjectNGFieldset,
     kLayoutObjectNGFlexibleBox,
+    kLayoutObjectNGGrid,
     kLayoutObjectNGMixin,
     kLayoutObjectNGListItem,
     kLayoutObjectNGInsideListMarker,

third_party/blink/renderer/core/layout/layout_object_factory.cc

@@ -11,6 +11,7 @@
 #include "third_party/blink/renderer/core/layout/layout_fieldset.h"
 #include "third_party/blink/renderer/core/layout/layout_file_upload_control.h"
 #include "third_party/blink/renderer/core/layout/layout_flexible_box.h"
+#include "third_party/blink/renderer/core/layout/layout_grid.h"
 #include "third_party/blink/renderer/core/layout/layout_inside_list_marker.h"
 #include "third_party/blink/renderer/core/layout/layout_list_item.h"
 #include "third_party/blink/renderer/core/layout/layout_outside_list_marker.h"
@@ -24,6 +25,7 @@
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_block_flow.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_fieldset.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_flexible_box.h"
+#include "third_party/blink/renderer/core/layout/ng/layout_ng_grid.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_progress.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_table_caption.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_table_cell.h"
@@ -107,6 +109,14 @@ LayoutBlock* LayoutObjectFactory::CreateFlexibleBox(Node& node,
       node, style, legacy, disable_ng_for_type);
 }
 
+LayoutBlock* LayoutObjectFactory::CreateGrid(Node& node,
+                                             const ComputedStyle& style,
+                                             LegacyLayout legacy) {
+  bool disable_ng_for_type = !RuntimeEnabledFeatures::LayoutNGGridEnabled();
+  return CreateObject<LayoutBlock, LayoutNGGrid, LayoutGrid>(
+      node, style, legacy, disable_ng_for_type);
+}
+
 LayoutObject* LayoutObjectFactory::CreateListMarker(Node& node,
                                                     const ComputedStyle& style,
                                                     LegacyLayout legacy) {

third_party/blink/renderer/core/layout/layout_object_factory.h

@@ -44,6 +44,7 @@ class LayoutObjectFactory {
   static LayoutBlock* CreateFlexibleBox(Node&,
                                         const ComputedStyle&,
                                         LegacyLayout);
+  static LayoutBlock* CreateGrid(Node&, const ComputedStyle&, LegacyLayout);
   static LayoutObject* CreateListMarker(Node&,
                                         const ComputedStyle&,
                                         LegacyLayout);

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

+// Copyright 2020 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 "third_party/blink/renderer/core/layout/ng/layout_ng_grid.h"
+
+#include "third_party/blink/renderer/core/layout/ng/ng_layout_result.h"
+
+namespace blink {
+
+LayoutNGGrid::LayoutNGGrid(Element* element)
+    : LayoutNGMixin<LayoutBlock>(element) {}
+
+void LayoutNGGrid::UpdateBlockLayout(bool relayout_children) {
+  if (IsOutOfFlowPositioned()) {
+    UpdateOutOfFlowBlockLayout();
+    return;
+  }
+
+  UpdateInFlowBlockLayout();
+}
+
+}  // namespace blink

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

+// Copyright 2020 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 THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_LAYOUT_NG_GRID_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_LAYOUT_NG_GRID_H_
+
+#include "third_party/blink/renderer/core/core_export.h"
+#include "third_party/blink/renderer/core/layout/layout_block.h"
+#include "third_party/blink/renderer/core/layout/ng/layout_ng_mixin.h"
+
+namespace blink {
+
+class CORE_EXPORT LayoutNGGrid : public LayoutNGMixin<LayoutBlock> {
+ public:
+  explicit LayoutNGGrid(Element*);
+
+  void UpdateBlockLayout(bool relayout_children) override;
+
+  const char* GetName() const override { return "LayoutNGGrid"; }
+
+ protected:
+  bool IsOfType(LayoutObjectType type) const override {
+    return type == kLayoutObjectNGGrid ||
+           LayoutNGMixin<LayoutBlock>::IsOfType(type);
+  }
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_LAYOUT_NG_GRID_H_

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

+// Copyright 2020 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 "third_party/blink/renderer/core/layout/ng/ng_grid_layout_algorithm.h"
+
+namespace blink {
+
+NGGridLayoutAlgorithm::NGGridLayoutAlgorithm(
+    const NGLayoutAlgorithmParams& params)
+    : NGLayoutAlgorithm(params) {
+  DCHECK(params.space.IsNewFormattingContext());
+  DCHECK(!params.break_token);
+  container_builder_.SetIsNewFormattingContext(true);
+  container_builder_.SetInitialFragmentGeometry(params.fragment_geometry);
+}
+
+scoped_refptr<const NGLayoutResult> NGGridLayoutAlgorithm::Layout() {
+  return container_builder_.ToBoxFragment();
+}
+
+base::Optional<MinMaxSizes> NGGridLayoutAlgorithm::ComputeMinMaxSizes(
+    const MinMaxSizesInput& input) const {
+  base::Optional<MinMaxSizes> sizes;
+  return sizes;
+}
+
+}  // namespace blink

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

+// Copyright 2020 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 THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_NG_GRID_LAYOUT_ALGORITHM_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_NG_GRID_LAYOUT_ALGORITHM_H_
+
+#include "third_party/blink/renderer/core/layout/ng/ng_block_break_token.h"
+#include "third_party/blink/renderer/core/layout/ng/ng_box_fragment_builder.h"
+#include "third_party/blink/renderer/core/layout/ng/ng_layout_algorithm.h"
+
+namespace blink {
+
+class CORE_EXPORT NGGridLayoutAlgorithm
+    : public NGLayoutAlgorithm<NGBlockNode,
+                               NGBoxFragmentBuilder,
+                               NGBlockBreakToken> {
+ public:
+  explicit NGGridLayoutAlgorithm(const NGLayoutAlgorithmParams& params);
+
+  scoped_refptr<const NGLayoutResult> Layout() override;
+
+  base::Optional<MinMaxSizes> ComputeMinMaxSizes(
+      const MinMaxSizesInput&) const override;
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_NG_GRID_LAYOUT_ALGORITHM_H_

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -917,7 +917,7 @@
       // unit tests.
       name: "LayoutNG",
       // Keep this list in sync with the one in LayoutNGFlexBox below.
-      implied_by: ["LayoutNGBlockFragmentation", "LayoutNGFieldset", "LayoutNGFragmentItem", "LayoutNGLineCache", "EditingNG", "BidiCaretAffinity", "LayoutNGTable", "LayoutNGFragmentTraversal"],
+      implied_by: ["LayoutNGBlockFragmentation", "LayoutNGFieldset", "LayoutNGFragmentItem", "LayoutNGGrid", "LayoutNGLineCache", "EditingNG", "BidiCaretAffinity", "LayoutNGTable", "LayoutNGFragmentTraversal"],
       status: "stable",
     },
     {
@@ -928,7 +928,7 @@
     },
     {
       name: "LayoutNGFlexBox",
-      implied_by: ["LayoutNGBlockFragmentation", "LayoutNGFieldset", "LayoutNGFragmentItem", "LayoutNGLineCache", "EditingNG", "BidiCaretAffinity", "LayoutNGTable", "LayoutNGFragmentTraversal"],
+      implied_by: ["LayoutNGBlockFragmentation", "LayoutNGFieldset", "LayoutNGFragmentItem", "LayoutNGGrid", "LayoutNGLineCache", "EditingNG", "BidiCaretAffinity", "LayoutNGTable", "LayoutNGFragmentTraversal"],
       status: "experimental",
     },
     {
@@ -945,6 +945,9 @@
       // the layout object tree.
       name: "LayoutNGFragmentTraversal",
     },
+    {
+      name: "LayoutNGGrid",
+    },
     {
       name: "LayoutNGLineCache",
     },