Revert of [LayoutNG] Remove simple constructors from NGPhysicalConstraintSpace.

third_party/WebKit/Source/core/layout/ng/ng_physical_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 NGPhysicalConstraintSpace_h
 #define NGPhysicalConstraintSpace_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_units.h"
 #include "platform/heap/Handle.h"
@@ skipping 52 matching lines @@
   NGPhysicalConstraintSpace(
       NGPhysicalSize container_size,
       bool fixed_width,
       bool fixed_height,
       bool width_direction_triggers_scrollbar,
       bool height_direction_triggers_scrollbar,
       NGFragmentationType width_direction_fragmentation_type,
       NGFragmentationType height_direction_fragmentation_type,
       bool is_new_fc);
 
+  NGPhysicalConstraintSpace();
+  NGPhysicalConstraintSpace(NGPhysicalSize);
+
   NGPhysicalSize ContainerSize() const { return container_size_; }
 
   void AddExclusion(const NGExclusion*, unsigned options = 0);
   const HeapVector<Member<const NGExclusion>>& Exclusions(
       unsigned options = 0) const;
 
   DEFINE_INLINE_TRACE() { visitor->trace(exclusions_); }
 
  private:
   friend class NGConstraintSpace;
@@ skipping 10 matching lines @@
   // Whether the current constraint space is for the newly established
   // formatting Context
   unsigned is_new_fc_ : 1;
 
   HeapVector<Member<const NGExclusion>> exclusions_;
 };
 
 }  // namespace blink
 
 #endif  // NGPhysicalConstraintSpace_h