[LayoutNG] Fix incorrectly positioned empty blocks inside of new BFC

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 82 matching lines @@
   String ToString() const;
 };
 
 CORE_EXPORT inline std::ostream& operator<<(std::ostream& os,
                                             const NGLogicalOffset& value) {
   return os << value.ToString();
 }
 
 // NGPhysicalOffset is the position of a rect (typically a fragment) relative to
 // its parent rect in the physical coordinate system.
-struct NGPhysicalOffset {
+struct CORE_EXPORT NGPhysicalOffset {
   NGPhysicalOffset() {}
   NGPhysicalOffset(LayoutUnit left, LayoutUnit top) : left(left), top(top) {}
 
   LayoutUnit left;
   LayoutUnit top;
 
   NGPhysicalOffset operator+(const NGPhysicalOffset& other) const;
   NGPhysicalOffset& operator+=(const NGPhysicalOffset& other);
 
   NGPhysicalOffset operator-(const NGPhysicalOffset& other) const;
   NGPhysicalOffset& operator-=(const NGPhysicalOffset& other);
 
+  bool operator==(const NGPhysicalOffset& other) const;
+
   String ToString() const {
     return String::format("%dx%d", left.toInt(), top.toInt());
   }
 };
 
 struct CORE_EXPORT NGPhysicalSize {
   NGPhysicalSize() {}
   NGPhysicalSize(LayoutUnit width, LayoutUnit height)
       : width(width), height(height) {}
 
@@ skipping 256 matching lines @@
     if (position_matches)
       return position;
     else
       return container_size - position - length - margin_start - margin_end;
   }
 };
 
 }  // namespace blink
 
 #endif  // NGUnits_h