Revert of Add a new enable_nonblocking_io field trial param for QUIC (patchset...

Revert of Add a new enable_nonblocking_io field trial param for QUIC (patchset #6 id:120001 of https://codereview.chromium.org/938003003/)

Reason for revert:
Speculative revert to see whether this affects some tests that involve loading fonts in gfx_unittests (see failures at http://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%29%281%29).

Original issue's description:
> Add a new enable_nonblocking_io field trial param for QUIC which enables the new non-blocking IO support on windows.
>
> BUG=442392
>
> Committed: https://crrev.com/83e8c1477cf5d41928b8c9035f0c4812828752f4
> Cr-Commit-Position: refs/heads/master@{#318555}

TBR=rtenneti@chromium.org,rch@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=442392

Review URL: https://codereview.chromium.org/970513004

Cr-Commit-Position: refs/heads/master@{#318601}

chrome/browser/io_thread.cc

@@ -1032,8 +1032,6 @@ void IOThread::InitializeNetworkSessionParamsFromGlobals(
       &params->quic_enable_truncated_connection_ids);
   globals.quic_enable_connection_racing.CopyToIfSet(
       &params->quic_enable_connection_racing);
-  globals.quic_enable_non_blocking_io.CopyToIfSet(
-      &params->quic_enable_non_blocking_io);
   globals.quic_disable_disk_cache.CopyToIfSet(
       &params->quic_disable_disk_cache);
   globals.quic_socket_receive_buffer_size.CopyToIfSet(
@@ -1180,8 +1178,6 @@ void IOThread::ConfigureQuicGlobals(
         ShouldQuicEnableTruncatedConnectionIds(quic_trial_params));
     globals->quic_enable_connection_racing.set(
         ShouldQuicEnableConnectionRacing(quic_trial_params));
-    globals->quic_enable_non_blocking_io.set(
-        ShouldQuicEnableNonBlockingIO(quic_trial_params));
     globals->quic_disable_disk_cache.set(
         ShouldQuicDisableDiskCache(quic_trial_params));
     globals->enable_quic_port_selection.set(
@@ -1388,14 +1384,6 @@ bool IOThread::ShouldQuicEnableConnectionRacing(
       "true");
 }
 
-// static
-bool IOThread::ShouldQuicEnableNonBlockingIO(
-    const VariationParameters& quic_trial_params) {
-  return LowerCaseEqualsASCII(
-      GetVariationParam(quic_trial_params, "enable_non_blocking_io"),
-      "true");
-}
-
 // static
 bool IOThread::ShouldQuicDisableDiskCache(
     const VariationParameters& quic_trial_params) {

chrome/browser/io_thread.h

@@ -190,7 +190,6 @@ class IOThread : public content::BrowserThreadDelegate {
     Optional<float> quic_load_server_info_timeout_srtt_multiplier;
     Optional<bool> quic_enable_truncated_connection_ids;
     Optional<bool> quic_enable_connection_racing;
-    Optional<bool> quic_enable_non_blocking_io;
     Optional<bool> quic_disable_disk_cache;
     Optional<int> quic_socket_receive_buffer_size;
     Optional<size_t> quic_max_packet_length;
@@ -386,10 +385,6 @@ class IOThread : public content::BrowserThreadDelegate {
   static bool ShouldQuicEnableConnectionRacing(
       const VariationParameters& quic_trial_params);
 
-  // Returns true if QUIC's should use non-blocking IO.
-  static bool ShouldQuicEnableNonBlockingIO(
-      const VariationParameters& quic_trial_params);
-
   // Returns true if QUIC shouldn't load QUIC server information from the disk
   // cache.
   static bool ShouldQuicDisableDiskCache(

chrome/browser/io_thread_unittest.cc

@@ -139,7 +139,6 @@ TEST_F(IOThreadTest, EnableQuicFromFieldTrialGroup) {
   EXPECT_EQ(0.0f, params.quic_load_server_info_timeout_srtt_multiplier);
   EXPECT_FALSE(params.quic_enable_truncated_connection_ids);
   EXPECT_FALSE(params.quic_enable_connection_racing);
-  EXPECT_FALSE(params.quic_enable_non_blocking_io);
   EXPECT_FALSE(params.quic_disable_disk_cache);
   EXPECT_FALSE(IOThread::ShouldEnableQuicForDataReductionProxy());
 }
@@ -330,15 +329,6 @@ TEST_F(IOThreadTest, QuicEnableConnectionRacing) {
   EXPECT_TRUE(params.quic_enable_connection_racing);
 }
 
-TEST_F(IOThreadTest, QuicEnableNonBlockingIO) {
-  field_trial_group_ = "Enabled";
-  field_trial_params_["enable_non_blocking_io"] = "true";
-  ConfigureQuicGlobals();
-  net::HttpNetworkSession::Params params;
-  InitializeNetworkSessionParams(&params);
-  EXPECT_TRUE(params.quic_enable_non_blocking_io);
-}
-
 TEST_F(IOThreadTest, QuicDisableDiskCache) {
   field_trial_group_ = "Enabled";
   field_trial_params_["disable_disk_cache"] = "true";

net/http/http_network_session.cc

@@ -94,7 +94,6 @@ HttpNetworkSession::Params::Params()
       quic_load_server_info_timeout_srtt_multiplier(0.0f),
       quic_enable_truncated_connection_ids(false),
       quic_enable_connection_racing(false),
-      quic_enable_non_blocking_io(false),
       quic_disable_disk_cache(false),
       quic_socket_receive_buffer_size(kDefaultSocketReceiveBuffer),
       quic_clock(NULL),
@@ -143,7 +142,6 @@ HttpNetworkSession::HttpNetworkSession(const Params& params)
           params.quic_load_server_info_timeout_srtt_multiplier,
           params.quic_enable_truncated_connection_ids,
           params.quic_enable_connection_racing,
-          params.quic_enable_non_blocking_io,
           params.quic_disable_disk_cache,
           params.quic_socket_receive_buffer_size,
           params.quic_connection_options),

net/http/http_network_session.h

@@ -121,7 +121,6 @@ class NET_EXPORT HttpNetworkSession
     float quic_load_server_info_timeout_srtt_multiplier;
     bool quic_enable_truncated_connection_ids;
     bool quic_enable_connection_racing;
-    bool quic_enable_non_blocking_io;
     bool quic_disable_disk_cache;
     int quic_socket_receive_buffer_size;
     HostPortPair origin_to_force_quic_on;

net/quic/quic_stream_factory.cc

@@ -37,7 +37,6 @@
 #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"
@@ -598,7 +597,6 @@ QuicStreamFactory::QuicStreamFactory(
     float load_server_info_timeout_srtt_multiplier,
     bool enable_truncated_connection_ids,
     bool enable_connection_racing,
-    bool enable_non_blocking_io,
     bool disable_disk_cache,
     int socket_receive_buffer_size,
     const QuicTagVector& connection_options)
@@ -623,7 +621,6 @@ QuicStreamFactory::QuicStreamFactory(
           load_server_info_timeout_srtt_multiplier),
       enable_truncated_connection_ids_(enable_truncated_connection_ids),
       enable_connection_racing_(enable_connection_racing),
-      enable_non_blocking_io_(enable_non_blocking_io),
       disable_disk_cache_(disable_disk_cache),
       socket_receive_buffer_size_(socket_receive_buffer_size),
       port_seed_(random_generator_->RandUint64()),
@@ -1018,13 +1015,6 @@ int QuicStreamFactory::CreateSession(const QuicServerId& server_id,
           base::Bind(&PortSuggester::SuggestPort, port_suggester),
           net_log.net_log(), net_log.source()));
 
-  if (enable_non_blocking_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(

net/quic/quic_stream_factory.h

@@ -109,7 +109,6 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
       float load_server_info_timeout_srtt_multiplier,
       bool enable_truncated_connection_ids,
       bool enable_connection_racing,
-      bool enable_non_blocking_io,
       bool disable_disk_cache,
       int socket_receive_buffer_size,
       const QuicTagVector& connection_options);
@@ -332,9 +331,6 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
   // config from the disk cache.
   bool enable_connection_racing_;
 
-  // Set if experimental non-blocking IO should be used on windows sockets.
-  bool enable_non_blocking_io_;
-
   // Set if we do not want to load server config from the disk cache.
   bool disable_disk_cache_;
 

net/quic/quic_stream_factory_test.cc

@@ -211,7 +211,6 @@ class QuicStreamFactoryTest : public ::testing::TestWithParam<TestParams> {
                  /*load_server_info_timeout_srtt_multiplier=*/0.0f,
                  /*enable_truncated_connection_ids=*/true,
                  /*enable_connection_racing=*/false,
-                 /*enable_non_blocking_io=*/true,
                  /*disable_disk_cache=*/false,
                  /*receive_buffer_size=*/0,
                  QuicTagVector()),