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

components/drive/file_change.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 "components/drive/file_change.h"
 
 #include <sstream>
 
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
@@ skipping 25 matching lines @@
       break;
     case FILE_TYPE_NO_INFO:
       // Keeps it as "no_info".
       break;
   }
   return base::StringPrintf("%s:%s", change_string, type_string);
 }
 
 FileChange::ChangeList::ChangeList() {
 }
+FileChange::ChangeList::ChangeList(const ChangeList& other) = default;
 FileChange::ChangeList::~ChangeList() {
 }
 
 void FileChange::ChangeList::Update(const Change& new_change) {
   if (list_.empty()) {
     list_.push_back(new_change);
     return;
   }
 
   Change& last = list_.back();
@@ skipping 89 matching lines @@
   ss << "{ ";
   for (FileChange::Map::const_iterator it = map_.begin(); it != map_.end();
        it++) {
     ss << it->first.value() << ": " << it->second.DebugString() << ", ";
   }
   ss << "}";
   return ss.str();
 }
 
 }  // namespace drive