Add simple reading to TlsConnection

This patch implements a ReceiveMessage method for TlsConnectionPosix,
that simply checks if bytes are pending and then reads them if so,
reporting any errors that occur.

Change-Id: If9c453cd466c235c502ed16deedac3b7538a6a46
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/1816287
Reviewed-by: Jordan Bayles <jophba@chromium.org>
Reviewed-by: Yuri Wiitala <miu@chromium.org>
Reviewed-by: Ryan Keane <rwkeane@google.com>
Commit-Queue: Jordan Bayles <jophba@chromium.org>
diff --git a/platform/api/tls_connection.cc b/platform/api/tls_connection.cc
index 0696e4f..ee0258c 100644
--- a/platform/api/tls_connection.cc
+++ b/platform/api/tls_connection.cc
@@ -42,14 +42,14 @@
   });
 }
 
-void TlsConnection::OnRead(std::vector<uint8_t> message) {
+void TlsConnection::OnRead(std::vector<uint8_t> block) {
   if (!client_) {
     return;
   }
 
-  task_runner_->PostTask([m = std::move(message), this]() mutable {
+  task_runner_->PostTask([b = std::move(block), this]() mutable {
     // TODO(issues/71): |this| may be invalid at this point.
-    this->client_->OnRead(this, std::move(m));
+    this->client_->OnRead(this, std::move(b));
   });
 }