[LayoutNG] Compute baseline from fragment tree

third_party/WebKit/Source/core/layout/ng/ng_block_node.cc

Index: third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc b/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
index 771d4b449c00ae8661b59847ac5bb3008f25436e..861872a6c20fa79c9748915d4dea136478d835a0 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_block_node.cc
@@ -360,9 +360,64 @@ RefPtr<NGLayoutResult> NGBlockNode::RunOldLayout(
       .SetDirection(box_->StyleRef().Direction())
       .SetWritingMode(writing_mode)
       .SetOverflowSize(overflow_size);
+  CopyBaselinesFromOldLayout(constraint_space, &builder);
   return builder.ToBoxFragment();
 }
 
+void NGBlockNode::CopyBaselinesFromOldLayout(
+    const NGConstraintSpace& constraint_space,
+    NGFragmentBuilder* builder) {
+  const Vector<NGBaselineRequest>& requests =
+      constraint_space.BaselineRequests();
+  if (requests.IsEmpty())
+    return;
+
+  for (const auto& request : requests) {
+    switch (request.algorithm_type) {
+      case NGBaselineAlgorithmType::kAtomicInline:
+        AddAtomicInlineBaselineFromOldLayout(request, false, builder);
+        break;
+      case NGBaselineAlgorithmType::kAtomicInlineForFirstLine:
+        AddAtomicInlineBaselineFromOldLayout(request, true, builder);
+        break;
+      case NGBaselineAlgorithmType::kFirstLine: {
+        int position = box_->FirstLineBoxBaseline();
+        if (position != -1) {
+          builder->AddBaseline(request.algorithm_type, request.baseline_type,
+                               LayoutUnit(position));
+        }
+        break;
+      }
+    }
+  }
+}
+
+void NGBlockNode::AddAtomicInlineBaselineFromOldLayout(
+    const NGBaselineRequest& request,
+    bool is_first_line,
+    NGFragmentBuilder* builder) {
+  LineDirectionMode line_direction =
+      IsHorizontalWritingMode(builder->WritingMode())
+          ? LineDirectionMode::kHorizontalLine
+          : LineDirectionMode::kVerticalLine;
+  LayoutUnit position = LayoutUnit(box_->BaselinePosition(
+      request.baseline_type, is_first_line, line_direction));
+
+  // Some form controls return 0 for BaselinePosition() if 'display:block'.
+  // Blocks without line boxes should not produce baselines.
+  if (!position && !box_->IsAtomicInlineLevel() &&
+      !box_->IsLayoutNGBlockFlow() &&
+      box_->InlineBlockBaseline(line_direction) == -1) {
+    return;
+  }
+
+  // BaselinePosition() uses margin edge for atomic inlines.
+  if (box_->IsAtomicInlineLevel())
+    position -= box_->MarginOver();
+
+  builder->AddBaseline(request.algorithm_type, request.baseline_type, position);
+}
+
 void NGBlockNode::UseOldOutOfFlowPositioning() {
   DCHECK(box_->IsOutOfFlowPositioned());
   box_->ContainingBlock()->InsertPositionedObject(box_);