[LayoutNG] Enable DCHECK inside of NGConstraintSpace::CreateFromLayoutObject.

This also makes the function accept a LayoutBlock instead as well.

Unittests which call NGConstraintSpace::CreateFromLayoutObject on a LayoutObject
are updated to ensure that the LayoutObject is a new formatting context.

Should have no behaviour change.

Change-Id: Ibaeffaecd47b37474fc426f80b006592a3257de8
Reviewed-on: https://chromium-review.googlesource.com/c/1473393
Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Christian Biesinger <cbiesinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#632815}

third_party/blink/renderer/core/layout/ng/inline/ng_inline_layout_algorithm_test.cc

@@ -253,6 +253,7 @@ TEST_F(NGInlineLayoutAlgorithmTest, MAYBE_VerticalAlignBottomReplaced) {
     <style>
     html { font-size: 10px; }
     img { vertical-align: bottom; }
+    #container { display: flow-root; }
     </style>
     <div id=container><img src="#" width="96" height="96"></div>
   )HTML");

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

@@ -34,11 +34,6 @@ bool LayoutNGBlockFlow::IsOfType(LayoutObjectType type) const {
 void LayoutNGBlockFlow::UpdateBlockLayout(bool relayout_children) {
   LayoutAnalyzer::BlockScope analyzer(*this);
 
-  // This block is an entry-point from the legacy engine to LayoutNG. This means
-  // that we need to be at a formatting context boundary, since NG and legacy
-  // don't cooperate on e.g. margin collapsing.
-  DCHECK(CreatesNewFormattingContext());
-
   if (IsOutOfFlowPositioned()) {
     UpdateOutOfFlowBlockLayout();
     return;

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

@@ -34,58 +34,52 @@ static_assert(sizeof(NGConstraintSpace) == sizeof(SameSizeAsNGConstraintSpace),
 }  // namespace
 
 NGConstraintSpace NGConstraintSpace::CreateFromLayoutObject(
-    const LayoutBox& box) {
-  const LayoutBlock* cb = box.ContainingBlock();
+    const LayoutBlock& block) {
+  // We should only ever create a constraint space from legacy layout if the
+  // object is a new formatting context.
+  DCHECK(block.CreatesNewFormattingContext());
 
+  const LayoutBlock* cb = block.ContainingBlock();
   LayoutUnit available_logical_width =
-      LayoutBoxUtils::AvailableLogicalWidth(box, cb);
+      LayoutBoxUtils::AvailableLogicalWidth(block, cb);
   LayoutUnit available_logical_height =
-      LayoutBoxUtils::AvailableLogicalHeight(box, cb);
+      LayoutBoxUtils::AvailableLogicalHeight(block, cb);
   NGLogicalSize percentage_size = {available_logical_width,
                                    available_logical_height};
   NGLogicalSize available_size = percentage_size;
 
   bool fixed_inline = false, fixed_block = false;
   bool fixed_block_is_definite = true;
-  if (box.HasOverrideLogicalWidth()) {
-    available_size.inline_size = box.OverrideLogicalWidth();
+  if (block.HasOverrideLogicalWidth()) {
+    available_size.inline_size = block.OverrideLogicalWidth();
     fixed_inline = true;
   }
-  if (box.HasOverrideLogicalHeight()) {
-    available_size.block_size = box.OverrideLogicalHeight();
+  if (block.HasOverrideLogicalHeight()) {
+    available_size.block_size = block.OverrideLogicalHeight();
     fixed_block = true;
   }
-  if (box.IsFlexItem() && fixed_block) {
+  if (block.IsFlexItem() && fixed_block) {
     // The flexbox-specific behavior is in addition to regular definite-ness, so
     // if the flex item would normally have a definite height it should keep it.
     fixed_block_is_definite =
-        ToLayoutFlexibleBox(box.Parent())
-            ->UseOverrideLogicalHeightForPerentageResolution(box) ||
-        (box.IsLayoutBlock() && ToLayoutBlock(box).HasDefiniteLogicalHeight());
+        ToLayoutFlexibleBox(block.Parent())
+            ->UseOverrideLogicalHeightForPerentageResolution(block) ||
+        block.HasDefiniteLogicalHeight();
   }
 
-  bool is_new_fc = true;
-  // TODO(ikilpatrick): This DCHECK needs to be enabled once we've switched
-  // LayoutTableCell, etc over to LayoutNG.
-  //
-  // We currently need to "force" LayoutNG roots to be formatting contexts so
-  // that floats have layout performed on them.
-  //
-  // DCHECK(is_new_fc,
-  //  box.IsLayoutBlock() && ToLayoutBlock(box).CreatesNewFormattingContext());
-
-  auto writing_mode = box.StyleRef().GetWritingMode();
+  const ComputedStyle& style = block.StyleRef();
+  auto writing_mode = style.GetWritingMode();
   bool parallel_containing_block = IsParallelWritingMode(
       cb ? cb->StyleRef().GetWritingMode() : writing_mode, writing_mode);
-  NGConstraintSpaceBuilder builder(writing_mode, writing_mode, is_new_fc,
+  NGConstraintSpaceBuilder builder(writing_mode, writing_mode,
+                                   /* is_new_fc */ true,
                                    !parallel_containing_block);
 
-  if (!box.IsWritingModeRoot() || box.IsGridItem()) {
+  if (!block.IsWritingModeRoot() || block.IsGridItem()) {
     // Add all types because we don't know which baselines will be requested.
-    FontBaseline baseline_type = box.StyleRef().GetFontBaseline();
+    FontBaseline baseline_type = style.GetFontBaseline();
     bool synthesize_inline_block_baseline =
-        box.IsLayoutBlock() &&
-        ToLayoutBlock(box).UseLogicalBottomMarginEdgeForInlineBlockBaseline();
+        block.UseLogicalBottomMarginEdgeForInlineBlockBaseline();
     if (!synthesize_inline_block_baseline) {
       builder.AddBaselineRequest(
           {NGBaselineAlgorithmType::kAtomicInline, baseline_type});
@@ -100,8 +94,8 @@ NGConstraintSpace NGConstraintSpace::CreateFromLayoutObject(
       .SetIsFixedSizeBlock(fixed_block)
       .SetFixedSizeBlockIsDefinite(fixed_block_is_definite)
       .SetIsShrinkToFit(
-          box.SizesLogicalWidthToFitContent(box.StyleRef().LogicalWidth()))
-      .SetTextDirection(box.StyleRef().Direction())
+          block.SizesLogicalWidthToFitContent(style.LogicalWidth()))
+      .SetTextDirection(style.Direction())
       .ToConstraintSpace();
 }
 

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

@@ -21,7 +21,7 @@
 
 namespace blink {
 
-class LayoutBox;
+class LayoutBlock;
 class NGConstraintSpaceBuilder;
 
 enum NGFragmentationType {
@@ -136,7 +136,7 @@ class CORE_EXPORT NGConstraintSpace final {
   // Creates NGConstraintSpace representing LayoutObject's containing block.
   // This should live on NGBlockNode or another layout bridge and probably take
   // a root NGConstraintSpace.
-  static NGConstraintSpace CreateFromLayoutObject(const LayoutBox&);
+  static NGConstraintSpace CreateFromLayoutObject(const LayoutBlock&);
 
   const NGExclusionSpace& ExclusionSpace() const { return exclusion_space_; }