Server push cancellation: add a finch trial parameter

net/tools/quic/quic_simple_dispatcher.cc

Index: net/tools/quic/quic_simple_dispatcher.cc
diff --git a/net/tools/quic/quic_simple_dispatcher.cc b/net/tools/quic/quic_simple_dispatcher.cc
index cab2925d5f1c02a9d9b1985e1e77364a8a3b447f..e173624489e04fdc01456aeb92fe98e9f67c67d0 100644
--- a/net/tools/quic/quic_simple_dispatcher.cc
+++ b/net/tools/quic/quic_simple_dispatcher.cc
@@ -26,6 +26,26 @@ QuicSimpleDispatcher::QuicSimpleDispatcher(
 
 QuicSimpleDispatcher::~QuicSimpleDispatcher() {}
 
+int QuicSimpleDispatcher::GetRstErrorCount(
+    QuicRstStreamErrorCode error_code) const {
+  auto it = rst_error_map_.find(error_code);
+  if (it == rst_error_map_.end()) {
+    return 0;
+  } else {
+    return it->second;
+  }
+}
+
+void QuicSimpleDispatcher::OnRstStreamReceived(
+    const QuicRstStreamFrame& frame) {
+  auto it = rst_error_map_.find(frame.error_code);
+  if (it == rst_error_map_.end()) {
+    rst_error_map_.insert(std::make_pair(frame.error_code, 1));
+  } else {
+    it->second++;
+  }
+}
+
 QuicServerSessionBase* QuicSimpleDispatcher::CreateQuicSession(
     QuicConnectionId connection_id,
     const QuicSocketAddress& client_address) {