Create scaffolding for experimenting with PCC. Protected by FLAGS_quic_reloadable_flag_quic_enable…

net/tools/quic/end_to_end_test.cc

Index: net/tools/quic/end_to_end_test.cc
diff --git a/net/tools/quic/end_to_end_test.cc b/net/tools/quic/end_to_end_test.cc
index 46e1ee910f9a426114582279f150de05ee4a9eb6..13b22ca5d5afd70182847a0edb3a287d0dca24c7 100644
--- a/net/tools/quic/end_to_end_test.cc
+++ b/net/tools/quic/end_to_end_test.cc
@@ -166,7 +166,8 @@ std::vector<TestParams> GetTestParams() {
   std::vector<TestParams> params;
   for (bool server_uses_stateless_rejects_if_peer_supported : {true, false}) {
     for (bool client_supports_stateless_rejects : {true, false}) {
-      for (const QuicTag congestion_control_tag : {kRENO, kTBBR, kQBIC}) {
+      for (const QuicTag congestion_control_tag :
+           {kRENO, kTBBR, kQBIC, kTPCC}) {
         for (bool disable_hpack_dynamic_table : {false}) {
           for (bool force_hol_blocking : {true, false}) {
             for (bool use_cheap_stateless_reject : {true, false}) {
@@ -425,6 +426,10 @@ class EndToEndTest : public QuicTestWithParam<TestParams> {
         FLAGS_quic_reloadable_flag_quic_enable_cubic_per_ack_updates) {
       copt.push_back(kCPAU);
     }
+    if (GetParam().congestion_control_tag == kTPCC &&
+        FLAGS_quic_reloadable_flag_quic_enable_pcc) {
+      copt.push_back(kTPCC);
+    }
 
     if (support_server_push_) {
       copt.push_back(kSPSH);
@@ -1348,6 +1353,13 @@ TEST_P(EndToEndTest, SetIndependentMaxIncomingDynamicStreamsLimits) {
 TEST_P(EndToEndTest, NegotiateCongestionControl) {
   FLAGS_quic_reloadable_flag_quic_allow_new_bbr = true;
   ASSERT_TRUE(Initialize());
+
+  // For PCC, the underlying implementation may be a stub with a
+  // different name-tag.  Skip the rest of this test.
+  if (GetParam().congestion_control_tag == kTPCC) {
+    return;
+  }
+
   EXPECT_TRUE(client_->client()->WaitForCryptoHandshakeConfirmed());
 
   CongestionControlType expected_congestion_control_type = kReno;