[net] Add a typemap for net::IPAddress

To resolve code review comments from https://codereview.chromium.org/2675033002/diff/280001/chrome/browser/media/router/mojo/media_router.mojom

Create an ip_address.mojom to be used by media_router.mojom

BUG=698423

Review-Url: https://codereview.chromium.org/2745643002
Cr-Commit-Position: refs/heads/master@{#456115}

net/interfaces/BUILD.gn

@@ -7,6 +7,7 @@ import("//mojo/public/tools/bindings/mojom.gni")
 mojom("interfaces") {
   sources = [
     "host_resolver_service.mojom",
+    "ip_address.mojom",
     "proxy_resolver_service.mojom",
   ]
   public_deps = [

net/interfaces/OWNERS

 per-file *.mojom=set noparent
 per-file *.mojom=file://ipc/SECURITY_OWNERS
+per-file *_struct_traits*.*=set noparent
+per-file *_struct_traits*.*=file://ipc/SECURITY_OWNERS
+per-file *.typemap=set noparent
+per-file *.typemap=file://ipc/SECURITY_OWNERS

net/interfaces/ip_address.mojom

+// 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.
+
+module net.interfaces;
+
+// Mirror of net::IPAddress.
+struct IPAddress {
+   // IP address as a numeric value from most to least significant byte.
+   // Will be of length 4 for IPv4 addresses and 16 for IPv6.
+   array<uint8> address;
+};

net/interfaces/ip_address.typemap

+# 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.
+
+mojom = "//net/interfaces/ip_address.mojom"
+public_headers = [ "//net/base/ip_address.h" ]
+traits_headers = [ "//net/interfaces/ip_address_struct_traits.h" ]
+sources = [
+  "//net/interfaces/ip_address_struct_traits.cc",
+]
+type_mappings = [ "net.interfaces.IPAddress=net::IPAddress" ]
+public_deps = [
+  "//net",
+]

net/interfaces/ip_address_struct_traits.cc

+// 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.
+
+#include "net/interfaces/ip_address_struct_traits.h"
+
+namespace mojo {
+// static
+bool StructTraits<net::interfaces::IPAddressDataView, net::IPAddress>::Read(
+    net::interfaces::IPAddressDataView data,
+    net::IPAddress* out) {
+  std::vector<uint8_t> bytes;
+  if (!data.ReadAddress(&bytes))
+    return false;
+
+  *out = net::IPAddress(bytes);
+  return out->IsValid();
+}
+
+}  // namespace mojo

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 bool Read(net::interfaces::IPAddressDataView obj, net::IPAddress* out);
+};
+
+}  // namespace mojo
+
+#endif  // NET_INTERFACES_IP_ADDRESS_STRUCT_TRAITS_H_

net/interfaces/typemaps.gni

@@ -4,5 +4,6 @@
 
 typemaps = [
   "//net/interfaces/host_resolver.typemap",
+  "//net/interfaces/ip_address.typemap",
   "//net/interfaces/proxy_resolver.typemap",
 ]