Fixed some cctest flakiness on mac.

src/debug-agent.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 47 matching lines @@
     // would be that the port is already in use so this avoids a busy loop and
     // make the agent take over the port when it becomes free.
     if (!bound) {
       terminate_now_->Wait(kOneSecondInMicros);
     }
   }
 
   // Accept connections on the bound port.
   while (!terminate_) {
     bool ok = server_->Listen(1);
+    listening_->Signal();
     if (ok) {
       // Accept the new connection.
       Socket* client = server_->Accept();
       ok = client != NULL;
       if (ok) {
         // Create and start a new session.
         CreateSession(client);
       }
     }
   }
 }
 
 
 void DebuggerAgent::Shutdown() {
   // Set the termination flag.
   terminate_ = true;
 
   // Signal termination and make the server exit either its listen call or its
   // binding loop. This makes sure that no new sessions can be established.
   terminate_now_->Signal();
   server_->Shutdown();
   Join();
 
   // Close existing session if any.
   CloseSession();
 }
 
 
+void DebuggerAgent::WaitUntilListening() {
+  listening_->Wait();
+}
+
 void DebuggerAgent::CreateSession(Socket* client) {
   ScopedLock with(session_access_);
 
   // If another session is already established terminate this one.
   if (session_ != NULL) {
     static const char* message = "Remote debugging session already active\r\n";
 
     client->Send(message, strlen(message));
     delete client;
     return;
@@ skipping 303 matching lines @@
       return total_received;
     }
     total_received += received;
   }
   return total_received;
 }
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_DEBUGGER_SUPPORT