Top down version of algorithm to position margins and floats in LayoutNG

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

Index: third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.cc b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.cc
index ac99cdd46c2c8c7e3304277d7a1a78bca7833097..e35cee1649d36187cc10c7ce69b6f8c22d636783 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.cc
@@ -23,6 +23,7 @@ NGConstraintSpaceBuilder::NGConstraintSpaceBuilder(
       fragmentation_type_(parent_space->BlockFragmentationType()),
       is_new_fc_(parent_space->IsNewFormattingContext()),
       text_direction_(static_cast<unsigned>(parent_space->Direction())),
+      bfc_offset_(parent_space->bfc_offset_),
       exclusions_(parent_space->Exclusions()) {}
 
 NGConstraintSpaceBuilder::NGConstraintSpaceBuilder(NGWritingMode writing_mode)
@@ -57,6 +58,12 @@ NGConstraintSpaceBuilder& NGConstraintSpaceBuilder::SetTextDirection(
   return *this;
 }
 
+NGConstraintSpaceBuilder& NGConstraintSpaceBuilder::SetMarginStrut(
+    const NGMarginStrut& margin_strut) {
+  margin_strut_ = margin_strut;
+  return *this;
+}
+
 NGConstraintSpaceBuilder& NGConstraintSpaceBuilder::SetIsFixedSizeInline(
     bool is_fixed_size_inline) {
   is_fixed_size_inline_ = is_fixed_size_inline;
@@ -119,6 +126,9 @@ NGConstraintSpace* NGConstraintSpaceBuilder::ToConstraintSpace() {
   bool is_in_parallel_flow = (parent_writing_mode_ == kHorizontalTopBottom) ==
                              (writing_mode_ == kHorizontalTopBottom);
 
+  NGMarginStrut margin_strut = is_new_fc_ ? NGMarginStrut() : margin_strut_;
+  NGLogicalOffset bfc_offset = is_new_fc_ ? NGLogicalOffset() : bfc_offset_;
+
   if (is_in_parallel_flow) {
     return new NGConstraintSpace(
         static_cast<NGWritingMode>(writing_mode_),
@@ -131,7 +141,7 @@ NGConstraintSpace* NGConstraintSpaceBuilder::ToConstraintSpace() {
         is_inline_direction_triggers_scrollbar_,
         is_block_direction_triggers_scrollbar_,
         static_cast<NGFragmentationType>(fragmentation_type_), is_new_fc_,
-        exclusions);
+        margin_strut, bfc_offset, exclusions);
   }
 
   return new NGConstraintSpace(
@@ -145,7 +155,7 @@ NGConstraintSpace* NGConstraintSpaceBuilder::ToConstraintSpace() {
       is_block_direction_triggers_scrollbar_,
       is_inline_direction_triggers_scrollbar_,
       static_cast<NGFragmentationType>(fragmentation_type_), is_new_fc_,
-      exclusions);
+      margin_strut, bfc_offset, exclusions);
 }
 
 }  // namespace blink