Revert of Make the default ctor of rtc::Thread, protected

webrtc/rtc_base/socket_unittest.cc

 /*
  *  Copyright 2007 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 663 matching lines @@
   EXPECT_EQ(client->GetRemoteAddress(), accepted->GetLocalAddress());
 
   // Do an i/o operation, triggering an eventual callback.
   EXPECT_FALSE(sink.Check(accepted.get(), SSE_READ));
   char buf[1024] = {0};
 
   EXPECT_EQ(1024, client->Send(buf, 1024));
   EXPECT_FALSE(sink.Check(accepted.get(), SSE_READ));
 
   // Shouldn't signal when blocked in a thread Send, where process_io is false.
-  std::unique_ptr<Thread> thread(Thread::CreateWithSocketServer());
+  std::unique_ptr<Thread> thread(new Thread());
   thread->Start();
   Sleeper sleeper;
   TypedMessageData<AsyncSocket*> data(client.get());
   thread->Send(RTC_FROM_HERE, &sleeper, 0, &data);
   EXPECT_FALSE(sink.Check(accepted.get(), SSE_READ));
 
   // But should signal when process_io is true.
   EXPECT_TRUE_WAIT((sink.Check(accepted.get(), SSE_READ)), kTimeout);
   EXPECT_LT(0, accepted->Recv(buf, 1024, nullptr));
 }
@@ skipping 342 matching lines @@
   socket->RecvFrom(buffer, 3, nullptr, &recv_timestamp_2);
 
   int64_t system_time_diff = send_time_2 - send_time_1;
   int64_t recv_timestamp_diff = recv_timestamp_2 - recv_timestamp_1;
   // Compare against the system time at the point of sending, because
   // SleepMs may not sleep for exactly the requested time.
   EXPECT_NEAR(system_time_diff, recv_timestamp_diff, 10000);
 }
 
 }  // namespace rtc