Add new constructor for TestUDPPort

The new constructor exposes an already existing constructor,
and is used to create a (test) UDPPort
with a socket...so that one does not (really) need a
socket factory.

Bug: b/339018639
Change-Id: Ib591fe6ae61519fe29cdea819192694448b071e0
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/356141
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42571}

p2p/BUILD.gn

@@ -1014,6 +1014,7 @@ if (rtc_include_tests) {
       "../rtc_base:task_queue_for_test",
       "../rtc_base:threading",
       "../rtc_base/memory:always_valid_pointer",
+      "//third_party/abseil-cpp/absl/memory",
       "//third_party/abseil-cpp/absl/strings:string_view",
     ]
   }

p2p/base/fake_port_allocator.h

@@ -16,6 +16,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/memory/memory.h"
 #include "absl/strings/string_view.h"
 #include "p2p/base/basic_packet_socket_factory.h"
 #include "p2p/base/port_allocator.h"
@@ -47,6 +48,18 @@ class TestUDPPort : public UDPPort {
     return port;
   }
 
+  static std::unique_ptr<TestUDPPort> Create(
+      const PortParametersRef& args,
+      rtc::AsyncPacketSocket* socket,
+      bool emit_localhost_for_anyaddress) {
+    auto port = absl::WrapUnique(
+        new TestUDPPort(args, socket, emit_localhost_for_anyaddress));
+    if (!port->Init()) {
+      return nullptr;
+    }
+    return port;
+  }
+
  protected:
   TestUDPPort(const PortParametersRef& args,
               uint16_t min_port,
@@ -57,6 +70,14 @@ class TestUDPPort : public UDPPort {
                 min_port,
                 max_port,
                 emit_localhost_for_anyaddress) {}
+
+  TestUDPPort(const PortParametersRef& args,
+              rtc::AsyncPacketSocket* socket,
+              bool emit_localhost_for_anyaddress)
+      : UDPPort(args,
+                webrtc::IceCandidateType::kHost,
+                socket,
+                emit_localhost_for_anyaddress) {}
 };
 
 // A FakePortAllocatorSession can be used with either a real or fake socket