Add mock QUIC transport to runner

The mock QUIC transport used has a very simple record layer: A record
starts with a single byte (either 'H' or 'A') identifying the record to
be handshake or application data, then a 4-byte network order integer
indicating the length of the payload, followed by the encryption secret
that would be used for protecting that payload, followed by the payload
itself. The encoded length is only the length of the payload, not that
of the payload and secret (or the whole record).

Bug: 293
Change-Id: Icb706a94ef1ad77e86ef8728b73db8832ee65e1b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/39144
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/ssl/test/CMakeLists.txt b/ssl/test/CMakeLists.txt
index ebc16f1..bb9bd81 100644
--- a/ssl/test/CMakeLists.txt
+++ b/ssl/test/CMakeLists.txt
@@ -6,6 +6,7 @@
   async_bio.cc
   bssl_shim.cc
   handshake_util.cc
+  mock_quic_transport.cc
   packeted_bio.cc
   settings_writer.cc
   test_config.cc
@@ -23,6 +24,7 @@
     async_bio.cc
     handshake_util.cc
     handshaker.cc
+    mock_quic_transport.cc
     packeted_bio.cc
     settings_writer.cc
     test_config.cc