[LayoutNG] Fix enum values to conform to kEnumName in style guide.

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_macros.h"
 #include "core/layout/ng/ng_physical_constraint_space.h"
@@ skipping 90 matching lines @@
   // If specified a layout should produce a Fragment which fragments at the
   // blockSize if possible.
   NGFragmentationType BlockFragmentationType() const;
 
   // Modifies constraint space to account for a placed fragment. Depending on
   // the shape of the fragment this will either modify the inline or block
   // size, or add an exclusion.
   void Subtract(const NGFragment*);
 
   NGLayoutOpportunityIterator* LayoutOpportunities(
-      unsigned clear = NGClearNone,
+      unsigned clear = kNGClearNone,
       bool for_inline_or_bfc = false);
 
   DEFINE_INLINE_VIRTUAL_TRACE() { visitor->trace(physical_space_); }
 
   NGConstraintSpace* ChildSpace(const ComputedStyle* style) const;
 
   String ToString() const;
 
  private:
   Member<NGPhysicalConstraintSpace> physical_space_;
   NGLogicalOffset offset_;
   unsigned writing_mode_ : 3;
   unsigned direction_ : 1;
 };
 
 inline std::ostream& operator<<(std::ostream& stream,
                                 const NGConstraintSpace& value) {
   return stream << value.ToString();
 }
 
 }  // namespace blink
 
 #endif  // NGConstraintSpace_h