Remove workaround in AutoSocketServerThread that isn't needed anymore.

Cleanup steps for the Connection class have changed as of:
https://webrtc-review.googlesource.com/c/src/+/249941

However, it turns out that the PortTest suite still needs it, so the
workaround has migrated to there.

Bug: none
Change-Id: Ia68f47b6c65b3a8fd5e8c04d70a43d15ba1a6422
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/250223
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35894}

p2p/base/port_unittest.cc

@@ -415,6 +415,13 @@ class PortTest : public ::testing::Test, public sigslot::has_slots<> {
         role_conflict_(false),
         ports_destroyed_(0) {}
 
+  ~PortTest() {
+    // Workaround for tests that trigger async destruction of objects that we
+    // need to give an opportunity here to run, before proceeding with other
+    // teardown.
+    rtc::Thread::Current()->ProcessMessages(0);
+  }
+
  protected:
   std::string password() { return password_; }
 

rtc_base/thread.cc

@@ -1236,11 +1236,6 @@ AutoSocketServerThread::AutoSocketServerThread(SocketServer* ss)
 
 AutoSocketServerThread::~AutoSocketServerThread() {
   RTC_DCHECK(ThreadManager::Instance()->CurrentThread() == this);
-  // Some tests post destroy messages to this thread. To avoid memory
-  // leaks, we have to process those messages. In particular
-  // P2PTransportChannelPingTest, relying on the message posted in
-  // cricket::Connection::Destroy.
-  ProcessMessages(0);
   // Stop and destroy the thread before clearing it as the current thread.
   // Sometimes there are messages left in the Thread that will be
   // destroyed by DoDestroy, and sometimes the destructors of the message and/or