Add QuicFramer and friends.

net/quic/crypto/quic_decrypter.cc

Index: net/quic/crypto/quic_decrypter.cc
diff --git a/net/quic/crypto/quic_decrypter.cc b/net/quic/crypto/quic_decrypter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..997a31177863b90aae306592268678048f32c3c2
--- /dev/null
+++ b/net/quic/crypto/quic_decrypter.cc
@@ -0,0 +1,21 @@
+// 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/quic/crypto/quic_decrypter.h"
+#include "net/quic/crypto/null_decrypter.h"
+
+namespace net {
+
+// static
+QuicDecrypter* QuicDecrypter::Create(CryptoTag algorithm) {
+  switch (algorithm) {
+    case kNULL:
+      return new NullDecrypter();
+    default:
+      LOG(FATAL) << "Unsupported algorithm: " << algorithm;
+      return NULL;
+  }
+}
+
+}  // namespace net