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

components/signin/core/browser/account_info.h

 // Copyright 2015 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 COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_INFO_H_
 #define COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_INFO_H_
 
 #include <string>
 
 // Information about a specific account.
 struct AccountInfo {
   AccountInfo();
+  AccountInfo(const AccountInfo& other);
   ~AccountInfo();
 
   std::string account_id;  // The account ID used by OAuth2TokenService.
   std::string gaia;
   std::string email;
   std::string full_name;
   std::string given_name;
   std::string hosted_domain;
   std::string locale;
   std::string picture_url;
   bool is_child_account;
 
   bool IsValid() const;
   // Updates the empty fields of |this| with |other|. Returns whether at least
   // one field was updated.
   bool UpdateWith(const AccountInfo& other);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_INFO_H_