chrome: Add out-of-line copy ctors for complex classes.

chrome/browser/prefs/session_startup_pref.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_PREFS_SESSION_STARTUP_PREF_H__
 #define CHROME_BROWSER_PREFS_SESSION_STARTUP_PREF_H__
 
 #include <vector>
 
 #include "url/gurl.h"
@@ skipping 47 matching lines @@
   static bool URLsAreManaged(PrefService* prefs);
 
   // Whether the startup type has not been overridden from its default.
   static bool TypeIsDefault(PrefService* prefs);
 
   // Converts an integer pref value to a SessionStartupPref::Type.
   static SessionStartupPref::Type PrefValueToType(int pref_value);
 
   explicit SessionStartupPref(Type type);
 
+  SessionStartupPref(const SessionStartupPref& other);
+
   ~SessionStartupPref();
 
   // What to do on startup.
   Type type;
 
   // The URLs to restore. Only used if type == URLS.
   std::vector<GURL> urls;
 };
 
 #endif  // CHROME_BROWSER_PREFS_SESSION_STARTUP_PREF_H__