Pass CancellationToken to Http2Connection SetupAsync (#70906)

* Pass cancellation token to Http2Connection SetupAsync

* PR feedback

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

@@ -174,7 +174,7 @@ public Http2Connection(HttpConnectionPool pool, Stream stream)
 
         private object SyncObject => _httpStreams;
 
-        public async ValueTask SetupAsync()
+        public async ValueTask SetupAsync(CancellationToken cancellationToken)
         {
             try
             {
@@ -208,7 +208,7 @@ public async ValueTask SetupAsync()
                 BinaryPrimitives.WriteUInt32BigEndian(_outgoingBuffer.AvailableSpan, windowUpdateAmount);
                 _outgoingBuffer.Commit(4);
 
-                await _stream.WriteAsync(_outgoingBuffer.ActiveMemory).ConfigureAwait(false);
+                await _stream.WriteAsync(_outgoingBuffer.ActiveMemory, cancellationToken).ConfigureAwait(false);
                 _rttEstimator.OnInitialSettingsSent();
                 _outgoingBuffer.Discard(_outgoingBuffer.ActiveLength);
 
@@ -217,6 +217,13 @@ public async ValueTask SetupAsync()
             catch (Exception e)
             {
                 Dispose();
+
+                if (e is OperationCanceledException oce && oce.CancellationToken == cancellationToken)
+                {
+                    // Note, AddHttp2ConnectionAsync handles this OCE separately so don't wrap it.
+                    throw;
+                }
+
                 throw new IOException(SR.net_http_http2_connection_not_established, e);
             }
 

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnectionPool.cs

@@ -1561,11 +1561,17 @@ private async ValueTask<Http2Connection> ConstructHttp2ConnectionAsync(Stream st
             Http2Connection http2Connection = new Http2Connection(this, stream);
             try
             {
-                await http2Connection.SetupAsync().ConfigureAwait(false);
+                await http2Connection.SetupAsync(cancellationToken).ConfigureAwait(false);
             }
             catch (Exception e)
             {
                 // Note, SetupAsync will dispose the connection if there is an exception.
+                if (e is OperationCanceledException oce && oce.CancellationToken == cancellationToken)
+                {
+                    // Note, AddHttp2ConnectionAsync handles this OCE separatly so don't wrap it.
+                    throw;
+                }
+
                 throw new HttpRequestException(SR.net_http_client_execution_error, e);
             }