[layoutng] Create a more correct constraint space for children

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.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 NGConstraintSpace_h
 #define NGConstraintSpace_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_units.h"
 #include "wtf/DoublyLinkedList.h"
@@ skipping 35 matching lines @@
  public:
   NGExclusion();
   ~NGExclusion() {}
 };
 
 class CORE_EXPORT NGConstraintSpace {
  public:
   NGConstraintSpace(NGLogicalSize container_size);
   virtual ~NGConstraintSpace() {}
 
+  // Constructs a new constraint space based on an old one with a new size but
+  // the same exclusions.
+  NGConstraintSpace(const NGConstraintSpace&, NGLogicalSize container_size);
+
   // Constructs Layout NG constraint space from legacy layout object.
   static NGConstraintSpace fromLayoutObject(const LayoutBox&);
 
   void addExclusion(const NGExclusion, unsigned options = 0);
   void setOverflowTriggersScrollbar(bool inlineTriggers, bool blockTriggers);
   void setFixedSize(bool inlineFixed, bool blockFixed);
   void setFragmentationType(NGFragmentationType);
 
   // Size of the container. Used for the following three cases:
   // 1) Percentage resolution.
@@ skipping 65 matching lines @@
 
  private:
   const NGConstraintSpace* constraint_space_;
   unsigned clear_;
   bool for_inline_or_bfc_;
 };
 
 }  // namespace blink
 
 #endif  // NGConstraintSpace_h