Remove SocketData and now only pass the dart port to epoll.

runtime/bin/eventhandler_macos.cc

Index: runtime/bin/eventhandler_macos.cc
diff --git a/runtime/bin/eventhandler_macos.cc b/runtime/bin/eventhandler_macos.cc
index a61a0d4acc6b9556c3aae5f5e1724740cae41643..b7d4fde975e809c72cb93d7844d5ad59f4d36e99 100644
--- a/runtime/bin/eventhandler_macos.cc
+++ b/runtime/bin/eventhandler_macos.cc
@@ -408,13 +408,13 @@ void EventHandlerImplementation::Start(EventHandler* handler) {
 
 
 void EventHandlerImplementation::Shutdown() {
-  SendData(kShutdownId, 0, 0);
+  Notify(kShutdownId, 0, 0);
 }
 
 
-void EventHandlerImplementation::SendData(intptr_t id,
-                                          Dart_Port dart_port,
-                                          int64_t data) {
+void EventHandlerImplementation::Notify(intptr_t id,
+                                        Dart_Port dart_port,
+                                        int64_t data) {
   WakeupHandler(id, dart_port, data);
 }