Add Mojo interfaces for out-of-process proxy resolver.

net/interfaces/host_resolver_service.mojom

+// 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.
+
+// WARNING! Do NOT use this mojom. It is intended as a temporary interface to
+// implement out-of-process proxy resolution. If you wish to use a Mojo DNS
+// service, contact amistry@/sammc@ and net-dev to discuss a permanent Mojo DNS
+// interface.
+
+// Put Mojo definitions into their own namespace to avoid collisions with C++
+// definitions.
+// TODO(amistry): Resolve the conflict between these two sets of definitions.
+module net.interfaces;
+
+// Mirror of net::AddressFamily.
+enum AddressFamily {
+  ADDRESS_FAMILY_UNSPECIFIED,
+  ADDRESS_FAMILY_IPV4,
+  ADDRESS_FAMILY_IPV6,

[eroman, 2015/02/03 04:53:29]

I doubt this is actually going to be needed. That said no harm in having it
here.

[Anand Mistry (off Chromium), 2015/02/03 06:27:22]

Acknowledged.

+};
+
+// Mirror of net::HostResolver::RequestInfo.
+struct RequestInfo {

[eroman, 2015/02/03 04:53:29]

RequestInfo is fairly vague. How about HostResolverRequestInfo?

Is this namespaced to host_resolver_service or global for net.interfaces?

[Anand Mistry (off Chromium), 2015/02/03 06:27:22]

done.
global for net.interfaces. So this translates to
net::interfaces::HostResolverRequestInfo.

+  string host;
+  uint16 port;
+  AddressFamily address_family;
+  bool is_my_ip_address;
+};
+
+// Mirror of net::IPEndPoint.
+struct IPEndPoint {
+  // 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;
+  uint16 port;
+};
+
+// Mirror of net::AddressList.
+struct AddressList {
+  array<IPEndPoint> addresses;
+  string canonical_name;

[eroman, 2015/02/03 04:53:29]

I don't believe canonical_name is needed.

[Anand Mistry (off Chromium), 2015/02/03 06:27:22]

Removed.

I saw the comment about crbug.com/126134, but it looks like this is still used
in a few places. With this gone, does a new instance of AddressList need to call
AddressList::SetDefaultCanonicalName()?

[eroman, 2015/02/04 01:25:19]

I was thinking more in terms of "is this needed by proxy resolver". And the
answer to that is "no".
I would say keep cname out for now, since I don't think any clients will be
needing it.

[Anand Mistry (off Chromium), 2015/02/04 04:05:31]

Acknowledged.

+};
+
+interface HostResolverService {
+  // Use a HostResolveRequestClient instead of returning a result so we can
+  // cancel in-flight requests by destroying the client.  IPC requests in Mojo
+  // cannot be cancelled directly.
+  // TODO(amistry): Add BoundNetLog.
+  Resolve(RequestInfo request_info, HostResolveRequestClient client);
+};
+
+interface HostResolveRequestClient {

[eroman, 2015/02/03 04:53:29]

I would epected HostResolverRequestClient rather than HostResolveRequestClient.

[Anand Mistry (off Chromium), 2015/02/03 06:27:22]

Done.

+  // |error| is a value in net::Error.
+  ReportResult(int32 error, AddressList? result);
+};