Update VirtualSocketServerTest to use a fake clock.

webrtc/base/thread.cc

 /*
  *  Copyright 2004 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 453 matching lines @@
     ++iter;
   }
 
   MessageQueue::Clear(phandler, id, removed);
 }
 
 #if !defined(WEBRTC_MAC)
 // Note that these methods have a separate implementation for mac and ios
 // defined in webrtc/base/thread_darwin.mm.
 bool Thread::ProcessMessages(int cmsLoop) {
+  // Using ProcessMessages with a custom clock for testing and a time greater
+  // than 0 doesn't work, since it's not guaranteed to advance the custom
+  // clock's time, and may get stuck in an infinite loop.
+  RTC_DCHECK(GetClockForTesting() == nullptr || cmsLoop == 0 ||
+             cmsLoop == kForever);
   int64_t msEnd = (kForever == cmsLoop) ? 0 : TimeAfter(cmsLoop);
   int cmsNext = cmsLoop;
 
   while (true) {
     Message msg;
     if (!Get(&msg, cmsNext))
       return !IsQuitting();
     Dispatch(&msg);
 
     if (cmsLoop != kForever) {
@@ skipping 60 matching lines @@
   // P2PTransportChannelPingTest, relying on the message posted in
   // cricket::Connection::Destroy.
   ProcessMessages(0);
   rtc::ThreadManager::Instance()->SetCurrentThread(old_thread_);
   if (old_thread_) {
     MessageQueueManager::Add(old_thread_);
   }
 }
 
 }  // namespace rtc