Revert of Add a whitelist for QUIC hosts.

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 cf17f98e1d49cca00f7b61e7e075ccc67c1afa93..cc7872f5efc962fa7e2d6533fe823dad312db444 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -1178,8 +1178,6 @@
       &params->quic_idle_connection_timeout_seconds);
   globals.quic_disable_preconnect_if_0rtt.CopyToIfSet(
       &params->quic_disable_preconnect_if_0rtt);
-  if (!globals.quic_host_whitelist.empty())
-    params->quic_host_whitelist = globals.quic_host_whitelist;
 
   globals.origin_to_force_quic_on.CopyToIfSet(
       &params->origin_to_force_quic_on);
@@ -1319,8 +1317,6 @@
     }
     globals->quic_disable_preconnect_if_0rtt.set(
         ShouldQuicDisablePreConnectIfZeroRtt(quic_trial_params));
-    globals->quic_host_whitelist =
-        GetQuicHostWhitelist(command_line, quic_trial_params);
   }
 
   size_t max_packet_length = GetQuicMaxPacketLength(command_line,
@@ -1578,24 +1574,6 @@
   return base::LowerCaseEqualsASCII(
       GetVariationParam(quic_trial_params, "disable_preconnect_if_0rtt"),
       "true");
-}
-
-std::unordered_set<std::string> IOThread::GetQuicHostWhitelist(
-    const base::CommandLine& command_line,
-    const VariationParameters& quic_trial_params) {
-  std::string whitelist;
-  if (command_line.HasSwitch(switches::kQuicHostWhitelist)) {
-    whitelist = command_line.GetSwitchValueASCII(switches::kQuicHostWhitelist);
-  } else {
-    whitelist = GetVariationParam(quic_trial_params, "quic_host_whitelist");
-  }
-  std::unordered_set<std::string> hosts;
-  for (const std::string& host :base::SplitString(whitelist, ",",
-                                                  base::TRIM_WHITESPACE,
-                                                  base::SPLIT_WANT_ALL)) {
-    hosts.insert(host);
-  }
-  return hosts;
 }
 
 size_t IOThread::GetQuicMaxPacketLength(