tools/gn: Add out-of-line copy ctors for complex classes.

tools/gn/substitution_pattern.h

 // Copyright 2014 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 TOOLS_GN_SUBSTITUTION_PATTERN_H_
 #define TOOLS_GN_SUBSTITUTION_PATTERN_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 16 matching lines @@
       return type == other.type && literal == other.literal;
     }
 
     SubstitutionType type;
 
     // When type_ == LITERAL, this specifies the literal.
     std::string literal;
   };
 
   SubstitutionPattern();
+  SubstitutionPattern(const SubstitutionPattern& other);
   ~SubstitutionPattern();
 
   // Parses the given string and fills in the pattern. The pattern must only
   // be initialized once. On failure, returns false and sets the error.
   bool Parse(const Value& value, Err* err);
   bool Parse(const std::string& str, const ParseNode* origin, Err* err);
 
   // Makes a pattern given a hardcoded string. Will assert if the string is
   // not a valid pattern.
   static SubstitutionPattern MakeForTest(const char* str);
@@ skipping 21 matching lines @@
   bool empty() const { return ranges_.empty(); }
 
  private:
   std::vector<Subrange> ranges_;
   const ParseNode* origin_;
 
   std::vector<SubstitutionType> required_types_;
 };
 
 #endif  // TOOLS_GN_SUBSTITUTION_PATTERN_H_