GTTF: Add missing virtual destructors.

chrome/browser/google_apis/auth_service_interface.h

 // Copyright (c) 2012 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 CHROME_BROWSER_GOOGLE_APIS_AUTH_SERVICE_INTERFACE_H_
 #define CHROME_BROWSER_GOOGLE_APIS_AUTH_SERVICE_INTERFACE_H_
 
 #include <string>
 
 #include "chrome/browser/google_apis/base_operations.h"
@@ skipping 37 matching lines @@
   // True if an OAuth2 refresh token is present. Its absence means that user
   // is not properly authenticated.
   // The refresh token is used to get the access token.
   virtual bool HasRefreshToken() const = 0;
 
   // Returns OAuth2 access token.
   virtual const std::string& access_token() const = 0;
 
   // Clears OAuth2 access token.
   virtual void ClearAccessToken() = 0;
+
+ protected:
+  virtual ~AuthServiceInterface() { }
 };
 
 }  // namespace google_apis
 
 #endif  // CHROME_BROWSER_GOOGLE_APIS_AUTH_SERVICE_INTERFACE_H_