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

third_party/WebKit/Source/core/layout/ng/ng_units.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 NGUnits_h
 #define NGUnits_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_writing_mode.h"
 #include "platform/LayoutUnit.h"
@@ skipping 285 matching lines @@
                           inline_start.toInt(), inline_end.toInt(),
                           block_start.toInt(), block_end.toInt());
   }
 };
 
 inline std::ostream& operator<<(std::ostream& stream, const NGBoxStrut& value) {
   return stream << value.ToString();
 }
 
 // This struct is used for the margin collapsing calculation.
-// TODO(glebl): Deprecated. It's being replaced by NGMarginStrut
-struct CORE_EXPORT NGDeprecatedMarginStrut {
-  LayoutUnit margin_block_start;
-  LayoutUnit margin_block_end;
-
-  LayoutUnit negative_margin_block_start;
-  LayoutUnit negative_margin_block_end;
-
-  LayoutUnit BlockEndSum() const;
-
-  void AppendMarginBlockStart(const LayoutUnit& value);
-  void AppendMarginBlockEnd(const LayoutUnit& value);
-  void SetMarginBlockStart(const LayoutUnit& value);
-  void SetMarginBlockEnd(const LayoutUnit& value);
-
-  bool IsEmpty() const;
-
-  String ToString() const;
-
-  bool operator==(const NGDeprecatedMarginStrut& other) const;
-};
-
-// This struct is used for the margin collapsing calculation.
 struct CORE_EXPORT NGMarginStrut {
   LayoutUnit margin;
   LayoutUnit negative_margin;
 
-  bool operator==(const NGMarginStrut& other) const;
-
+  // Appends negative or positive value to the current margin strut.
   void Append(const LayoutUnit& value);
 
-  LayoutUnit Collapse() const;
+  // Sum up negative and positive margins of this strut.
+  LayoutUnit Sum() const;
+
+  bool operator==(const NGMarginStrut& other) const;
 
   String ToString() const;
 };
 
 inline std::ostream& operator<<(std::ostream& stream,
                                 const NGMarginStrut& value) {
   return stream << value.ToString();
 }
 
 // Struct to represent a simple edge that has start and end.
@@ skipping 53 matching lines @@
     if (position_matches)
       return position;
     else
       return container_size - position - length - margin_start - margin_end;
   }
 };
 
 }  // namespace blink
 
 #endif  // NGUnits_h