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

chrome/browser/local_discovery/service_discovery_client.cc

 // Copyright 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.
 
 #include <stddef.h>
 
 #include "chrome/browser/local_discovery/service_discovery_client.h"
 
 namespace local_discovery {
 
 ServiceDescription::ServiceDescription() {
 }
 
+ServiceDescription::ServiceDescription(const ServiceDescription& other) =
+    default;
+
 ServiceDescription::~ServiceDescription() {
 }
 
 std::string ServiceDescription::instance_name() const {
   // TODO(noamsml): Once we have escaping working, get this to
   // parse escaped domains.
   size_t first_period = service_name.find_first_of('.');
   return service_name.substr(0, first_period);
 }
 
 std::string ServiceDescription::service_type() const {
   // TODO(noamsml): Once we have escaping working, get this to
   // parse escaped domains.
   size_t first_period = service_name.find_first_of('.');
   if (first_period == std::string::npos)
     return "";
   return service_name.substr(first_period+1);
 }
 
 }  // namespace local_discovery