WIP version of new margin collapsing logic + support of empty blocks with floats

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

Index: third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.h b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.h
index 5bbcbf7149f8e79ea569002429a5bb8e3dd3d341..c216512cdd0ca102174176e0442a37e2d265fd9d 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space_builder.h
@@ -44,6 +44,16 @@ class CORE_EXPORT NGConstraintSpaceBuilder final
 
   NGConstraintSpaceBuilder& SetWritingMode(NGWritingMode writing_mode);
 
+  NGConstraintSpaceBuilder& SetOffset(
+      const NGLogicalOffset& offset = NGLogicalOffset());
+
+  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.
@@ -54,7 +64,6 @@ class CORE_EXPORT NGConstraintSpaceBuilder final
 
   DEFINE_INLINE_TRACE() {}
 
- private:
   NGLogicalSize available_size_;
   NGLogicalSize percentage_resolution_size_;
   LayoutUnit fragmentainer_space_available_;
@@ -70,6 +79,8 @@ class CORE_EXPORT NGConstraintSpaceBuilder final
   unsigned is_new_fc_ : 1;
   unsigned text_direction_ : 1;
 
+  NGMarginStrut margin_strut_;
+  NGLogicalOffset bfc_offset_;
   std::shared_ptr<NGExclusions> exclusions_;
 };