Remove the no longer used kPACE connection option. No functional change.

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 55767a73ccc42be11fb5aca1574bbc6f027d6d32..46d0e3e85bb2b3a2f26c65eb7ad8bf5862ce3640 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -1342,9 +1342,6 @@ void IOThread::ConfigureQuicGlobals(
         ShouldEnableQuicPortSelection(command_line));
     globals->quic_connection_options =
         GetQuicConnectionOptions(command_line, quic_trial_params);
-    if (ShouldEnableQuicPacing(command_line, quic_trial_params)) {
-      globals->quic_connection_options.push_back(net::kPACE);
-    }
   }
 
   size_t max_packet_length = GetQuicMaxPacketLength(command_line,
@@ -1439,20 +1436,6 @@ bool IOThread::ShouldEnableQuicPortSelection(
   return false;  // Default to disabling port selection on all channels.
 }
 
-bool IOThread::ShouldEnableQuicPacing(
-    const base::CommandLine& command_line,
-    const VariationParameters& quic_trial_params) {
-  if (command_line.HasSwitch(switches::kEnableQuicPacing))
-    return true;
-
-  if (command_line.HasSwitch(switches::kDisableQuicPacing))
-    return false;
-
-  return LowerCaseEqualsASCII(
-      GetVariationParam(quic_trial_params, "enable_pacing"),
-      "true");
-}
-
 net::QuicTagVector IOThread::GetQuicConnectionOptions(
     const base::CommandLine& command_line,
     const VariationParameters& quic_trial_params) {