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

chrome/browser/extensions/extension_sync_data.cc

 // 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.
 
 #include "chrome/browser/extensions/extension_sync_data.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 116 matching lines @@
         LinkedAppIcons::GetLinkedAppIcons(&extension);
     for (const auto& icon : icons.icons) {
       LinkedAppIconInfo linked_icon;
       linked_icon.url = icon.url;
       linked_icon.size = icon.size;
       linked_icons_.push_back(linked_icon);
     }
   }
 }
 
+ExtensionSyncData::ExtensionSyncData(const ExtensionSyncData& other) = default;
+
 ExtensionSyncData::~ExtensionSyncData() {}
 
 // static
 scoped_ptr<ExtensionSyncData> ExtensionSyncData::CreateFromSyncData(
     const syncer::SyncData& sync_data) {
   scoped_ptr<ExtensionSyncData> data(new ExtensionSyncData);
   if (data->PopulateFromSyncData(sync_data))
     return data;
   return nullptr;
 }
@@ skipping 168 matching lines @@
 
   if (entity_specifics.has_extension())
     return PopulateFromExtensionSpecifics(entity_specifics.extension());
 
   LOG(ERROR) << "Attempt to sync bad EntitySpecifics: no extension data.";
   RecordBadSyncData(NO_EXTENSION_SPECIFICS);
   return false;
 }
 
 }  // namespace extensions