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

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

 // Copyright 2016 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 NGConstraintSpaceBuilder_h
 #define NGConstraintSpaceBuilder_h
 
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_units.h"
 
@@ skipping 26 matching lines @@
   NGConstraintSpaceBuilder& SetIsInlineDirectionTriggersScrollbar(
       bool is_inline_direction_triggers_scrollbar);
   NGConstraintSpaceBuilder& SetIsBlockDirectionTriggersScrollbar(
       bool is_block_direction_triggers_scrollbar);
 
   NGConstraintSpaceBuilder& SetFragmentationType(NGFragmentationType);
   NGConstraintSpaceBuilder& SetIsNewFormattingContext(bool is_new_fc);
 
   NGConstraintSpaceBuilder& SetWritingMode(NGWritingMode writing_mode);
 
+  NGConstraintSpaceBuilder& SetMarginStrut(const NGMarginStrut& margin_strut);
+
+  NGConstraintSpaceBuilder& SetBfcOffset(const NGLogicalOffset& offset) {
+    bfc_offset_ = offset;
+    return *this;
+  }
+
   // Creates a new constraint space. This may be called multiple times, for
   // example the constraint space will be different for a child which:
   //  - Establishes a new formatting context.
   //  - Is within a fragmentation container and needs its fragmentation offset
   //    updated.
   //  - Has its size is determined by its parent layout (flex, abs-pos).
   NGConstraintSpace* ToConstraintSpace();
 
   DEFINE_INLINE_TRACE() {}
 
  private:
   NGLogicalSize available_size_;
   NGLogicalSize percentage_resolution_size_;
   LayoutUnit fragmentainer_space_available_;
 
   unsigned writing_mode_ : 2;
   unsigned parent_writing_mode_ : 2;
   unsigned is_fixed_size_inline_ : 1;
   unsigned is_fixed_size_block_ : 1;
   unsigned is_shrink_to_fit_ : 1;
   unsigned is_inline_direction_triggers_scrollbar_ : 1;
   unsigned is_block_direction_triggers_scrollbar_ : 1;
   unsigned fragmentation_type_ : 2;
   unsigned is_new_fc_ : 1;
   unsigned text_direction_ : 1;
 
+  NGMarginStrut margin_strut_;
+  NGLogicalOffset bfc_offset_;
   std::shared_ptr<NGExclusions> exclusions_;
 };
 
 }  // namespace blink
 
 #endif  // NGConstraintSpaceBuilder