Remove a bunch of unused network flags.

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 4d12f2e3f0ca577350d571d9c1459d93102508f8..2f8dc338eafe76ac806829c3c025d348d0b43a45 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -188,12 +188,7 @@ scoped_ptr<net::HostResolver> CreateGlobalHostResolver(net::NetLog* net_log) {
   scoped_ptr<net::HostResolver> global_host_resolver(
       net::HostResolver::CreateSystemResolver(options, net_log));
 
-  // Determine if we should disable IPv6 support.
-  if (command_line.HasSwitch(switches::kEnableIPv6)) {
-    // Disable IPv6 probing.
-    global_host_resolver->SetDefaultAddressFamily(
-        net::ADDRESS_FAMILY_UNSPECIFIED);
-  } else if (command_line.HasSwitch(switches::kDisableIPv6)) {
+  if (command_line.HasSwitch(switches::kDisableIPv6)) {

[szym, 2014/02/19 00:13:29]

IMO if anything deserves to be left behind, it is --enable-ipv6.

If Chrome incorrectly disables IPv6, users cannot reach local IPv6-only
resources, so --enable-ipv6 is a last resort workaround.

In contrast, if Chrome incorrectly enables IPv6, it costs a few hundred
milliseconds in performance for every new socket. I don't think people will
bother to use the command-line flag to work around such a performance problem.

[willchan no longer on Chromium, 2014/02/19 00:21:43]

Oh, maybe I got this wrong. Did you think we should move *both* to
net-internals? Or just one and remove the other completely? I'm open to
whatever.

[szym, 2014/02/19 02:29:16]

In contrast to -async-dns (which can be moved to net-internals), we do not have
a persistent preference (in chrome://flags or group policy) that would allow
users to override this, so I'd prefer to leave --enable-ipv6 command line flag.

     global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
   }
 
@@ -773,11 +768,6 @@ void IOThread::InitializeNetworkOptions(const CommandLine& command_line) {
       net::WebSocketJob::set_websocket_over_spdy_enabled(true);
     }
 
-    if (command_line.HasSwitch(switches::kMaxSpdyConcurrentStreams)) {
-      globals_->max_spdy_concurrent_streams_limit.set(
-          GetSwitchValueAsInt(command_line,
-                              switches::kMaxSpdyConcurrentStreams));
-    }
     if (command_line.HasSwitch(switches::kTrustedSpdyProxy)) {
       globals_->trusted_spdy_proxy.set(
           command_line.GetSwitchValueASCII(switches::kTrustedSpdyProxy));
@@ -795,8 +785,6 @@ void IOThread::InitializeNetworkOptions(const CommandLine& command_line) {
       net::HttpStreamFactory::EnableNpnSpdy4a2();
     } else if (command_line.HasSwitch(switches::kDisableSpdy31)) {
       net::HttpStreamFactory::EnableNpnSpdy3();
-    } else if (command_line.HasSwitch(switches::kEnableSpdy2)) {
-      net::HttpStreamFactory::EnableNpnSpdy31WithSpdy2();
     } else if (command_line.HasSwitch(switches::kEnableNpnHttpOnly)) {
       net::HttpStreamFactory::EnableNpnHttpOnly();
     } else {
@@ -984,8 +972,6 @@ void IOThread::InitializeNetworkSessionParams(
 
   globals_->initial_max_spdy_concurrent_streams.CopyToIfSet(
       &params->spdy_initial_max_concurrent_streams);
-  globals_->max_spdy_concurrent_streams_limit.CopyToIfSet(
-      &params->spdy_max_concurrent_streams_limit);
   globals_->force_spdy_single_domain.CopyToIfSet(
       &params->force_spdy_single_domain);
   globals_->enable_spdy_ip_pooling.CopyToIfSet(