Extending the translation from ONC to Shill.

chromeos/test/data/network/valid_l2tpipsec_clientcert.onc

Index: chromeos/test/data/network/valid_l2tpipsec_clientcert.onc
diff --git a/chromeos/test/data/network/valid_l2tpipsec_clientcert.onc b/chromeos/test/data/network/valid_l2tpipsec_clientcert.onc
new file mode 100644
index 0000000000000000000000000000000000000000..5e6f2a0a3a23b5f1607ec36f60640835d1d916a0
--- /dev/null
+++ b/chromeos/test/data/network/valid_l2tpipsec_clientcert.onc
@@ -0,0 +1,25 @@
+{ "GUID": "guid",
+  "Type": "VPN",
+  "Name": "MyL2TPVPN",
+  "VPN": {
+      "Type": "L2TP-IPsec",
+      "Host": "some.host.org",
+      "IPsec": {
+          "AuthenticationType": "Cert",
+          "ClientCertType": "Pattern",
+          "ClientCertPattern": {
+              "EnrollmentURI": [ "my.enrollment.url" ],
+              "IssuerCARef": [
+                  "def",
+                  "abc"
+              ]
+          },
+          "IKEVersion": 1,
+          "SaveCredentials": true
+      },
+      "L2TP": {
+          "Username": "some username",
+          "Password": "some password"
+      }
+  }
+}