Add ClearanceOffset to LayoutNG Constraint space.

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 102 matching lines @@
   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());
   }
 };
 
+CORE_EXPORT inline std::ostream& operator<<(std::ostream& os,
+                                            const NGPhysicalOffset& value) {
+  return os << value.ToString();
+}
+
 struct CORE_EXPORT NGPhysicalSize {
   NGPhysicalSize() {}
   NGPhysicalSize(LayoutUnit width, LayoutUnit height)
       : width(width), height(height) {}
 
   LayoutUnit width;
   LayoutUnit height;
 
   NGLogicalSize ConvertToLogical(NGWritingMode mode) const;
 
@@ skipping 251 matching lines @@
     if (position_matches)
       return position;
     else
       return container_size - position - length - margin_start - margin_end;
   }
 };
 
 }  // namespace blink
 
 #endif  // NGUnits_h