Add close to input stream and cleanup socket and streams

runtime/bin/eventhandler_linux.h

Index: runtime/bin/eventhandler_linux.h
diff --git a/runtime/bin/eventhandler_linux.h b/runtime/bin/eventhandler_linux.h
index 219ff4e27263581da204ccf1460c41b91ed1a0e1..9cbb124428ba5251308335a2e84e8e605ab0003c 100644
--- a/runtime/bin/eventhandler_linux.h
+++ b/runtime/bin/eventhandler_linux.h
@@ -46,7 +46,7 @@ class SocketData {
     Unregister();
     flags_ = 0;
     close(fd_);
-    fd_ = 0;
+    fd_ = -1;
   }
 
   bool IsListeningSocket() { return (mask_ & (1 << kListeningSocket)) != 0; }
@@ -60,6 +60,7 @@ class SocketData {
   bool HasPollEvents() { return mask_ != 0; }
 
   void SetPortAndMask(Dart_Port port, intptr_t mask) {
+    ASSERT(fd_ != -1);
     port_ = port;
     mask_ = mask;
   }