[Chromecast] Reland "Ignore interfaces not used to connect to internet."

chromecast/net/net_util_cast.cc

Index: chromecast/net/net_util_cast.cc
diff --git a/chromecast/net/net_util_cast.cc b/chromecast/net/net_util_cast.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6e688316c8a46e3c290d6ecd6aef857f2a89fb51
--- /dev/null
+++ b/chromecast/net/net_util_cast.cc
@@ -0,0 +1,33 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromecast/net/net_util_cast.h"
+
+#include "base/command_line.h"
+#include "base/strings/string_split.h"
+#include "chromecast/base/cast_sys_info_util.h"
+#include "chromecast/net/net_switches.h"
+#include "chromecast/public/cast_sys_info.h"
+
+namespace chromecast {
+
+base::hash_set<std::string> GetIgnoredInterfaces() {
+  base::hash_set<std::string> ignored_interfaces;
+  scoped_ptr<CastSysInfo> sys_info = CreateSysInfo();
+  if (!sys_info->GetApInterface().empty())
+    ignored_interfaces.insert(sys_info->GetApInterface());
+
+  // Add interfaces from "netif-to-ignore" switch.
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  base::CommandLine::StringType netifs_to_ignore_str =
+      command_line->GetSwitchValueNative(switches::kNetifsToIgnore);
+  base::CommandLine::StringVector netifs_to_ignore_vector;
+  base::SplitString(netifs_to_ignore_str, ',', &netifs_to_ignore_vector);
+  for (const auto& netif : netifs_to_ignore_vector)
+    ignored_interfaces.insert(netif);
+
+  return ignored_interfaces;
+}
+
+}  // namespace chromecast