Introduce QuicTransportClient.OnDatagramReceived

Bug: 1011392
Change-Id: I1a3871505ae836adfbc393dfbe2ab028a0159817
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2000410Reviewed-by: Victor Vasiliev <vasilvv@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732375}

services/network/public/mojom/quic_transport.mojom

@@ -39,6 +39,9 @@ interface QuicTransport {
 
 // A mojo interface for the client of QuicTransport.
 interface QuicTransportClient {
+  // A datagram message is sent from the server.
+  OnDatagramReceived(mojo_base.mojom.ReadOnlyBuffer data);
+
   // Notifies that the server will not write data to the Stream for |stream_id|.
   // |fin_received| is true when FIN is received from the server.
   // Note that OnIncomingStreamClosed and OnOutgoingStreamClosed can both be

services/network/quic_transport.cc

@@ -513,7 +513,15 @@ void QuicTransport::OnIncomingUnidirectionalStreamAvailable() {
 }
 
 void QuicTransport::OnIncomingDatagramAvailable() {
-  // TODO(yhirano): Implement this.
+  if (torn_down_) {
+    return;
+  }
+
+  base::Optional<std::string> datagram = transport_->session()->ReadDatagram();
+  DCHECK(datagram);
+
+  client_->OnDatagramReceived(base::make_span(
+      reinterpret_cast<const uint8_t*>(datagram->data()), datagram->size()));
 }
 
 void QuicTransport::OnCanCreateNewOutgoingBidirectionalStream() {

services/network/quic_transport_unittest.cc

@@ -115,6 +115,7 @@ class TestClient final : public mojom::QuicTransportClient {
   }
 
   // mojom::QuicTransportClient implementation.
+  void OnDatagramReceived(base::span<const uint8_t> data) override {}
   void OnIncomingStreamClosed(uint32_t stream_id, bool fin_received) override {
     closed_incoming_streams_.insert(std::make_pair(stream_id, fin_received));
     if (quit_closure_for_incoming_stream_closure_) {
@@ -311,6 +312,9 @@ TEST_F(QuicTransportTest, SendDatagram) {
   EXPECT_TRUE(result);
 }
 
+// TODO(yhirano): Add a test for OnDatagramReceived. It would be difficult due
+// to the flaky nature of datagrams.
+
 TEST_F(QuicTransportTest, SendToolargeDatagram) {
   base::RunLoop run_loop_for_handshake;
   mojo::PendingRemote<mojom::QuicTransportHandshakeClient> handshake_client;

third_party/blink/renderer/modules/webtransport/quic_transport.cc

@@ -177,6 +177,12 @@ void QuicTransport::OnHandshakeFailed() {
   Dispose();
 }
 
+void QuicTransport::OnDatagramReceived(base::span<const uint8_t> data) {
+  DVLOG(1) << "QuicTransport::OnDatagramReceived(size: " << data.size()
+           << ") this =" << this;
+  // TODO(ricea): Implement this.
+}
+
 void QuicTransport::OnIncomingStreamClosed(uint32_t stream_id,
                                            bool fin_received) {
   DVLOG(1) << "QuicTransport::OnIncomingStreamClosed(" << stream_id << ", "

third_party/blink/renderer/modules/webtransport/quic_transport.h

@@ -5,6 +5,7 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBTRANSPORT_QUIC_TRANSPORT_H_
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBTRANSPORT_QUIC_TRANSPORT_H_
 
+#include "base/containers/span.h"
 #include "base/util/type_safety/pass_key.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
 #include "mojo/public/cpp/bindings/pending_remote.h"
@@ -60,6 +61,7 @@ class MODULES_EXPORT QuicTransport final
   void OnHandshakeFailed() override;
 
   // QuicTransportClient implementation
+  void OnDatagramReceived(base::span<const uint8_t> data) override;
   void OnIncomingStreamClosed(uint32_t stream_id, bool fin_received) override;
 
   // Implementation of ContextLifecycleObserver