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

tools/gn/pattern.h

 // Copyright (c) 2013 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_PATTERN_H_
 #define TOOLS_GN_PATTERN_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 29 matching lines @@
       }
     }
 
     Type type;
 
     // When type == LITERAL this is the text to match.
     std::string literal;
   };
 
   explicit Pattern(const std::string& s);
+  Pattern(const Pattern& other);
   ~Pattern();
 
   // Returns true if the current pattern matches the given string.
   bool MatchesString(const std::string& s) const;
 
  private:
   // allow_implicit_path_boundary determines if a path boundary should accept
   // matches at the beginning or end of the string.
   bool RecursiveMatch(const std::string& s,
                       size_t begin_char,
                       size_t subrange_index,
                       bool allow_implicit_path_boundary) const;
 
   std::vector<Subrange> subranges_;
 
   // Set to true when the subranges are "*foo" ("ANYTHING" followed by a
   // literal). This covers most patterns so we optimize for this.
   bool is_suffix_;
 };
 
 class PatternList {
  public:
   PatternList();
+  PatternList(const PatternList& other);
   ~PatternList();
 
   bool is_empty() const { return patterns_.empty(); }
 
   void Append(const Pattern& pattern);
 
   // Initializes the pattern list from a give list of pattern strings. Sets
   // |*err| on failure.
   void SetFromValue(const Value& v, Err* err);
 
   bool MatchesString(const std::string& s) const;
   bool MatchesValue(const Value& v) const;
 
  private:
   std::vector<Pattern> patterns_;
 };
 
 #endif  // TOOLS_GN_PATTERN_H_