Cap the number of pending accepts on Windows

runtime/bin/eventhandler_win.cc

Index: runtime/bin/eventhandler_win.cc
diff --git a/runtime/bin/eventhandler_win.cc b/runtime/bin/eventhandler_win.cc
index d3091f6d6198a81f31cc9f803b5303f205fc0885..db698a3c8831e637cb17e15fbeef1c242548d152 100644
--- a/runtime/bin/eventhandler_win.cc
+++ b/runtime/bin/eventhandler_win.cc
@@ -562,9 +562,12 @@ ClientSocket* ListenSocket::Accept() {
     accepted_count_--;
   }
 
-  if (!IsClosing()) {
-    if (!IssueAccept()) {
-      HandleError(this);
+  if (pending_accept_count_ < 5) {
+    // We have less than 5 pending accepts, queue another.
+    if (!IsClosing()) {
+      if (!IssueAccept()) {
+        HandleError(this);
+      }
     }
   }