Use ip_address helpers to get loopback IP.

This fixes use of undeclared identifier 'INADDR_LOOPBACK' when compiling fake_port_allocator.h on iOS.

Change-Id: Ia94080650058a3fdd7b63a6377e1097c7933fd22
Bug: webrtc:251890128
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/469400
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47597}

p2p/BUILD.gn

diff --git a/p2p/BUILD.gn b/p2p/BUILD.gn
index a3993ad..f9f3e0f 100644
--- a/p2p/BUILD.gn
+++ b/p2p/BUILD.gn
@@ -989,6 +989,7 @@
       "../rtc_base:async_packet_socket",
       "../rtc_base:checks",
       "../rtc_base:ip_address",
+      "../rtc_base:net_helpers",
       "../rtc_base:net_test_helpers",
       "../rtc_base:network",
       "../rtc_base:socket_factory",

p2p/test/fake_port_allocator.h

diff --git a/p2p/test/fake_port_allocator.h b/p2p/test/fake_port_allocator.h
index 8e27df9..8e473ff 100644
--- a/p2p/test/fake_port_allocator.h
+++ b/p2p/test/fake_port_allocator.h
@@ -32,6 +32,7 @@
 #include "rtc_base/async_packet_socket.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/ip_address.h"
+#include "rtc_base/net_helpers.h"
 #include "rtc_base/net_test_helpers.h"
 #include "rtc_base/network.h"
 #include "rtc_base/socket_factory.h"
@@ -109,14 +110,14 @@
         allocator_(allocator),
         network_thread_(network_thread),
         factory_(factory),
-        ipv4_network_("network", "unittest", IPAddress(INADDR_LOOPBACK), 32),
-        ipv6_network_("network", "unittest", IPAddress(in6addr_loopback), 64),
+        ipv4_network_("network", "unittest", GetLoopbackIP(AF_INET), 32),
+        ipv6_network_("network", "unittest", GetLoopbackIP(AF_INET6), 64),
         port_(),
         port_config_count_(0),
         stun_servers_(allocator->stun_servers()),
         turn_servers_(allocator->turn_servers()) {
-    ipv4_network_.AddIP(IPAddress(INADDR_LOOPBACK));
-    ipv6_network_.AddIP(IPAddress(in6addr_loopback));
+    ipv4_network_.AddIP(GetLoopbackIP(AF_INET));
+    ipv6_network_.AddIP(GetLoopbackIP(AF_INET6));
   }
 
   void SetCandidateFilter(uint32_t filter) override {