Change new List(n) to return fixed length list.

runtime/bin/socket_patch.dart

Index: runtime/bin/socket_patch.dart
diff --git a/runtime/bin/socket_patch.dart b/runtime/bin/socket_patch.dart
index a980f39ea19128e8adc6e2b5a4ce822f28142037..33fb37e0b1f43dbc2e14e1ad3eee8fd42107ff87 100644
--- a/runtime/bin/socket_patch.dart
+++ b/runtime/bin/socket_patch.dart
@@ -123,17 +123,17 @@ class _NativeSocket extends NativeFieldWrapperClass1 {
   }
 
   _NativeSocket.normal() : typeFlags = TYPE_NORMAL_SOCKET {
-    eventHandlers = new List.fixedLength(EVENT_COUNT + 1);
+    eventHandlers = new List(EVENT_COUNT + 1);
     _EventHandler._start();
   }
 
   _NativeSocket.listen() : typeFlags = TYPE_LISTENING_SOCKET {
-    eventHandlers = new List.fixedLength(EVENT_COUNT + 1);
+    eventHandlers = new List(EVENT_COUNT + 1);
     _EventHandler._start();
   }
 
   _NativeSocket.pipe() : typeFlags = TYPE_PIPE {
-    eventHandlers = new List.fixedLength(EVENT_COUNT + 1);
+    eventHandlers = new List(EVENT_COUNT + 1);
     _EventHandler._start();
   }