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

components/sessions/core/serialized_navigation_entry.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 "components/sessions/core/serialized_navigation_entry.h"
 
 #include <stddef.h>
 
 #include "base/pickle.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 12 matching lines @@
       has_post_data_(false),
       post_id_(-1),
       is_overriding_user_agent_(false),
       http_status_code_(0),
       is_restored_(false),
       blocked_state_(STATE_INVALID) {
   referrer_policy_ =
       SerializedNavigationDriver::Get()->GetDefaultReferrerPolicy();
 }
 
+SerializedNavigationEntry::SerializedNavigationEntry(
+    const SerializedNavigationEntry& other) = default;
+
 SerializedNavigationEntry::~SerializedNavigationEntry() {}
 
 SerializedNavigationEntry SerializedNavigationEntry::FromSyncData(
     int index,
     const sync_pb::TabNavigation& sync_data) {
   SerializedNavigationEntry navigation;
   navigation.index_ = index;
   navigation.unique_id_ = sync_data.unique_id();
   if (sync_data.has_correct_referrer_policy()) {
     navigation.referrer_url_ = GURL(sync_data.referrer());
@@ skipping 419 matching lines @@
           redirect_chain_[last_entry].spec());
     }
   }
 
   sync_data.set_is_restored(is_restored_);
 
   return sync_data;
 }
 
 }  // namespace sessions