QUIC: Add packet_reader_yield_after_duration_milliseconds field trial param.

components/network_session_configurator/network_session_configurator.cc

Index: components/network_session_configurator/network_session_configurator.cc
diff --git a/components/network_session_configurator/network_session_configurator.cc b/components/network_session_configurator/network_session_configurator.cc
index 48af1c0d290d9d0b496ec7e2bf7fda8c15615c9e..42379bac23346f322de6316bff032259463f427e 100644
--- a/components/network_session_configurator/network_session_configurator.cc
+++ b/components/network_session_configurator/network_session_configurator.cc
@@ -207,6 +207,18 @@ int GetQuicIdleConnectionTimeoutSeconds(
   return 0;
 }
 
+int GetQuicPacketReaderYieldAfterDurationMilliseconds(
+    const VariationParameters& quic_trial_params) {
+  int value;
+  if (base::StringToInt(
+          GetVariationParam(quic_trial_params,
+                            "packet_reader_yield_after_duration_milliseconds"),
+          &value)) {
+    return value;
+  }
+  return 0;
+}
+
 bool ShouldQuicDisablePreConnectIfZeroRtt(
     const VariationParameters& quic_trial_params) {
   return base::LowerCaseEqualsASCII(
@@ -321,6 +333,12 @@ void ConfigureQuicParams(base::StringPiece quic_trial_group,
       params->quic_idle_connection_timeout_seconds =
           idle_connection_timeout_seconds;
     }
+    int packet_reader_yield_after_duration_milliseconds =
+        GetQuicPacketReaderYieldAfterDurationMilliseconds(quic_trial_params);
+    if (packet_reader_yield_after_duration_milliseconds != 0) {
+      params->quic_packet_reader_yield_after_duration_milliseconds =
+          packet_reader_yield_after_duration_milliseconds;
+    }
     params->quic_disable_preconnect_if_0rtt =
         ShouldQuicDisablePreConnectIfZeroRtt(quic_trial_params);
     params->quic_host_whitelist = GetQuicHostWhitelist(quic_trial_params);