Add a new enable_nonblocking_io field trial param for QUIC

net/quic/quic_stream_factory.cc

Index: net/quic/quic_stream_factory.cc
diff --git a/net/quic/quic_stream_factory.cc b/net/quic/quic_stream_factory.cc
index 203f07ecb1646670ba0f517adadd23639d559671..8497b7c7fdf49fd3ca3d50823b865bb826b1fd56 100644
--- a/net/quic/quic_stream_factory.cc
+++ b/net/quic/quic_stream_factory.cc
@@ -37,6 +37,7 @@
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_server_id.h"
 #include "net/socket/client_socket_factory.h"
+#include "net/udp/udp_client_socket.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
@@ -596,6 +597,7 @@ QuicStreamFactory::QuicStreamFactory(
     float load_server_info_timeout_srtt_multiplier,
     bool enable_truncated_connection_ids,
     bool enable_connection_racing,
+    bool enable_nonblocking_io,
     bool disable_disk_cache,
     const QuicTagVector& connection_options)
     : require_confirmation_(true),
@@ -619,6 +621,7 @@ QuicStreamFactory::QuicStreamFactory(
           load_server_info_timeout_srtt_multiplier),
       enable_truncated_connection_ids_(enable_truncated_connection_ids),
       enable_connection_racing_(enable_connection_racing),
+      enable_nonblocking_io_(enable_nonblocking_io),
       disable_disk_cache_(disable_disk_cache),
       port_seed_(random_generator_->RandUint64()),
       check_persisted_supports_quic_(true),
@@ -1012,6 +1015,13 @@ int QuicStreamFactory::CreateSession(
           base::Bind(&PortSuggester::SuggestPort, port_suggester),
           net_log.net_log(), net_log.source()));
 
+  if (enable_nonblocking_io_ &&
+      client_socket_factory_ == ClientSocketFactory::GetDefaultFactory()) {
+#if defined(OS_WIN)
+    static_cast<UDPClientSocket*>(socket.get())->UseNonBlockingIO();
+#endif
+  }
+
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
   tracked_objects::ScopedTracker tracking_profile2(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(