Add GN targets for mojom generator

mojo/public/interfaces/bindings/tests/BUILD.gn

Index: mojo/public/interfaces/bindings/tests/BUILD.gn
diff --git a/mojo/public/interfaces/bindings/tests/BUILD.gn b/mojo/public/interfaces/bindings/tests/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..f394c8d69066e8ae3dcb445048d9f6e8785c75ca
--- /dev/null
+++ b/mojo/public/interfaces/bindings/tests/BUILD.gn
@@ -0,0 +1,17 @@
+# Copyright 2014 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.
+
+import("//mojo/public/tools/bindings/mojom.gni")
+
+mojom("test_interfaces") {
+  sources = [
+    "math_calculator.mojom",
+    "sample_factory.mojom",
+    "sample_import.mojom",
+    "sample_import2.mojom",
+    "sample_interfaces.mojom",
+    "sample_service.mojom",
+    "test_structs.mojom",
+  ]
+}