Add ResetModem method and call it once non_cellular activation is done.

chromeos/network/cros_network_functions.cc

Index: chromeos/network/cros_network_functions.cc
diff --git a/chromeos/network/cros_network_functions.cc b/chromeos/network/cros_network_functions.cc
index c7d02b12d0f51ac5516b1a99e126feb3c9f0eeea..350b837e091358512c741b71c2359b1da3970dcd 100644
--- a/chromeos/network/cros_network_functions.cc
+++ b/chromeos/network/cros_network_functions.cc
@@ -666,4 +666,12 @@ void CrosSetCarrier(const std::string& device_path,
       base::Bind(&OnNetworkActionError, callback, device_path));
 }
 
+// Resets the device.
+void CrosReset(const std::string& device_path) {
+  DBusThreadManager::Get()->GetShillDeviceClient()->Reset(
+      dbus::ObjectPath(device_path),
+      base::Bind(&DoNothing),
+      base::Bind(&IgnoreErrors));
+}
+
 }  // namespace chromeos