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

chromeos/network/cros_network_functions.h

Index: chromeos/network/cros_network_functions.h
diff --git a/chromeos/network/cros_network_functions.h b/chromeos/network/cros_network_functions.h
index 5ff93be77bb674d2463bb990618c3816aa119047..ddc44811956bcce971a47a93f2b9ee7d0c0eb1ec 100644
--- a/chromeos/network/cros_network_functions.h
+++ b/chromeos/network/cros_network_functions.h
@@ -262,6 +262,9 @@ CHROMEOS_EXPORT void CrosSetCarrier(const std::string& device_path,
                                     const std::string& carrier,
                                     const NetworkOperationCallback& callback);
 
+// Resets the device.
+CHROMEOS_EXPORT void CrosReset(const std::string& device_path);
+
 }  // namespace chromeos
 
 #endif  // CHROMEOS_NETWORK_CROS_NETWORK_FUNCTIONS_H_