Add QuicStrCat.

net/quic/platform/api/quic_str_cat.h

Index: net/quic/platform/api/quic_str_cat.h
diff --git a/net/quic/platform/api/quic_str_cat.h b/net/quic/platform/api/quic_str_cat.h
new file mode 100644
index 0000000000000000000000000000000000000000..cfbc67d6e77063d4218cb6737f5cdf55063938f3
--- /dev/null
+++ b/net/quic/platform/api/quic_str_cat.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2016 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.
+
+#ifndef NET_QUIC_PLATFORM_API_QUIC_STR_CAT_H_
+#define NET_QUIC_PLATFORM_API_QUIC_STR_CAT_H_
+
+#include "net/quic/platform/impl/quic_str_cat_impl.h"
+
+namespace net {
+
+template <typename... Args>
+inline std::string QuicStrCat(const Args&... args) {
+  return std::move(QuicStrCatImpl(std::forward<const Args&>(args)...));
+}
+
+}  // namespace net
+
+#endif  // NET_QUIC_PLATFORM_API_QUIC_STR_CAT_H_