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

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

Index: third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h b/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
index d1a7301598a7f732cc60104dc743c69eb7c4df04..bbe754be0f7d6e25037d8d9e0d0839c01452cfa7 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_fragment_builder.h
@@ -38,6 +38,8 @@ class CORE_EXPORT NGFragmentBuilder final
   NGFragmentBuilder& AddFloatingObject(NGFloatingObject*,
                                        const NGLogicalOffset&);
 
+  NGFragmentBuilder& SetBfcOffset(const NGLogicalOffset& offset);
+
   // Builder has non-trivial out-of-flow descendant methods.
   // These methods are building blocks for implementation of
   // out-of-flow descendants by layout algorithms.
@@ -92,11 +94,10 @@ class CORE_EXPORT NGFragmentBuilder final
   }
   bool HasBreakToken() const { return break_token_; }
 
-  // Sets MarginStrut for the resultant fragment.
-  NGFragmentBuilder& SetMarginStrutBlockStart(
-      const NGDeprecatedMarginStrut& from);
-  NGFragmentBuilder& SetMarginStrutBlockEnd(
-      const NGDeprecatedMarginStrut& from);
+  NGFragmentBuilder& SetEndMarginStrut(const NGMarginStrut& from) {
+    end_margin_strut_ = from;
+    return *this;
+  }
 
   // Offsets are not supposed to be set during fragment construction, so we
   // do not provide a setter here.
@@ -112,9 +113,12 @@ class CORE_EXPORT NGFragmentBuilder final
     return unpositioned_floats_;
   }
 
+  const WTF::Optional<NGLogicalOffset>& BfcOffset() const {
+    return bfc_offset_;
+  }
+
   DECLARE_VIRTUAL_TRACE();
 
- private:
   // Out-of-flow descendant placement information.
   // The generated fragment must compute NGStaticPosition for all
   // out-of-flow descendants.
@@ -142,8 +146,6 @@ class CORE_EXPORT NGFragmentBuilder final
   NGLogicalSize size_;
   NGLogicalSize overflow_;
 
-  NGDeprecatedMarginStrut margin_strut_;
-
   HeapVector<Member<NGPhysicalFragment>> children_;
   Vector<NGLogicalOffset> offsets_;
 
@@ -161,6 +163,9 @@ class CORE_EXPORT NGFragmentBuilder final
   HeapVector<Member<NGFloatingObject>> positioned_floats_;
 
   Member<NGBreakToken> break_token_;
+
+  WTF::Optional<NGLogicalOffset> bfc_offset_;
+  NGMarginStrut end_margin_strut_;
 };
 
 }  // namespace blink