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

components/proximity_auth/cryptauth/secure_message_delegate.cc

 // 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.
 
 #include "components/proximity_auth/cryptauth/secure_message_delegate.h"
 
 namespace proximity_auth {
 
 SecureMessageDelegate::SecureMessageDelegate() {
 }
 
 SecureMessageDelegate::~SecureMessageDelegate() {
 }
 
 SecureMessageDelegate::CreateOptions::CreateOptions() {
 }
 
+SecureMessageDelegate::CreateOptions::CreateOptions(
+    const CreateOptions& other) = default;
+
 SecureMessageDelegate::CreateOptions::~CreateOptions() {
 }
 
 SecureMessageDelegate::UnwrapOptions::UnwrapOptions() {
 }
 
 SecureMessageDelegate::UnwrapOptions::~UnwrapOptions() {
 }
 
 }  // proximity_auth