Add sessions to HttpServer.

runtime/bin/crypto_win.cc

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#define _CRT_RAND_S
+#include "bin/crypto.h"
+
+
+bool Crypto::GetRandomBytes(intptr_t count, uint8_t* buffer) {
+  uint32_t num;
+  intptr_t read = 0;
+  while (read < count) {
+    if (rand_s(&num) != 0) {
+      return false;
+    }
+    for (int i = 0; i < 4 && read < count; i++) {
+      buffer[read] = num >> (i * 8);
+      read++;
+    }
+  }
+  return true;
+}