Clang needs dtor in the cc file (build fix)

base/version.h

 // Copyright (c) 2011 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 BASE_VERSION_H_
 #define BASE_VERSION_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/base_api.h"
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 
 // Version represents a dotted version number, like "1.2.3.4", supporting
 // parsing and comparison.
 class BASE_API Version {
  public:
   // The only thing you can legally do to a default constructed
   // Version object is assign to it.
   Version();
 
+  ~Version();
+
   // Initializes from a decimal dotted version number, like "0.1.1".
   // Each component is limited to a uint16. Call IsValid() to learn
   // the outcome.
   explicit Version(const std::string& version_str);
 
   // Returns true if the object contains a valid version number.
   bool IsValid() const;
 
   // Returns NULL if the string is not in the proper format.
   // Caller is responsible for freeing the Version object once done.
@@ skipping 12 matching lines @@
   // Return the string representation of this version.
   const std::string GetString() const;
 
   const std::vector<uint16>& components() const { return components_; }
 
  private:
   std::vector<uint16> components_;
 };
 
 #endif  // BASE_VERSION_H_