Open a firewall hole when a TCP server or UDP socket is bound.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 713f3c1408e175cc873b758b7f8c209ff2870b9c..c0f83b413b599610fbadc8df8ba10e0faa5c0177 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2266,6 +2266,15 @@ const Experiment kExperiments[] = {
     kOsDesktop,
     SINGLE_VALUE_TYPE(switches::kV8PacMojoOutOfProcess),
   },
+#if defined(OS_CHROMEOS)
+  {
+    "enable-firewall-hole-punching",
+    IDS_FLAGS_ENABLE_FIREWALL_HOLE_PUNCHING_NAME,
+    IDS_FLAGS_ENABLE_FIREWALL_HOLE_PUNCHING_DESCRIPTION,
+    kOsCrOS,
+    SINGLE_VALUE_TYPE(chromeos::switches::kEnableFirewallHolePunching)
+  },
+#endif  // defined(OS_CHROMEOS)
 
   // NOTE: Adding new command-line switches requires adding corresponding
   // entries to enum "LoginCustomFlags" in histograms.xml. See note in