diff --git a/quic/test_tools/mock_random.cc b/quic/test_tools/mock_random.cc
new file mode 100644
index 0000000..a01a5a7
--- /dev/null
+++ b/quic/test_tools/mock_random.cc
@@ -0,0 +1,29 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/third_party/quiche/src/quic/test_tools/mock_random.h"
+
+#include <string.h>
+
+namespace quic {
+namespace test {
+
+MockRandom::MockRandom() : base_(0xDEADBEEF), increment_(0) {}
+
+MockRandom::MockRandom(uint32_t base) : base_(base), increment_(0) {}
+
+void MockRandom::RandBytes(void* data, size_t len) {
+  memset(data, increment_ + static_cast<uint8_t>('r'), len);
+}
+
+uint64_t MockRandom::RandUint64() {
+  return base_ + increment_;
+}
+
+void MockRandom::ChangeValue() {
+  increment_++;
+}
+
+}  // namespace test
+}  // namespace quic