Fix socket error reporting on Windows

runtime/bin/eventhandler_win.h

Index: runtime/bin/eventhandler_win.h
diff --git a/runtime/bin/eventhandler_win.h b/runtime/bin/eventhandler_win.h
index 1aa2339f455371d0c63ba717fef549f2a33959ec..7b4902fb381f3c41094fa02a61ce9c976db41dce 100644
--- a/runtime/bin/eventhandler_win.h
+++ b/runtime/bin/eventhandler_win.h
@@ -217,6 +217,7 @@ class Handle {
   Handle(HANDLE handle, Dart_Port port);
 
   virtual void AfterClose() = 0;
+  virtual void HandleIssueError();
 
   Type type_;
   HANDLE handle_;
@@ -260,6 +261,8 @@ class SocketHandle : public Handle {
   explicit SocketHandle(SOCKET s) : Handle(reinterpret_cast<HANDLE>(s)) {}
   SocketHandle(SOCKET s, Dart_Port port)
       : Handle(reinterpret_cast<HANDLE>(s), port) {}
+
+  virtual void HandleIssueError();
 };