Avoid heap allocations in IPAddress

net/interfaces/ip_address_struct_traits.h

 // Copyright 2017 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.
 
 #ifndef NET_INTERFACES_IP_ADDRESS_STRUCT_TRAITS_H_
 #define NET_INTERFACES_IP_ADDRESS_STRUCT_TRAITS_H_
 
 #include "mojo/public/cpp/bindings/struct_traits.h"
 #include "net/base/ip_address.h"
 #include "net/interfaces/ip_address.mojom.h"
 
 namespace mojo {
 template <>
 struct StructTraits<net::interfaces::IPAddressDataView, net::IPAddress> {
-  static const std::vector<uint8_t>& address(const net::IPAddress& ip_address) {
-    return ip_address.bytes();
+  static const std::vector<uint8_t> address(const net::IPAddress& ip_address) {
+    // TODO(rch): avoid creating a vector here.
+    return ip_address.BytesAsVector();
   }
 
   static bool Read(net::interfaces::IPAddressDataView obj, net::IPAddress* out);
 };
 
 }  // namespace mojo
 
 #endif  // NET_INTERFACES_IP_ADDRESS_STRUCT_TRAITS_H_