[mojo-bindings] Support reuse of native enum classes

components/mus/public/interfaces/gpu.typemap

Index: components/mus/public/interfaces/gpu.typemap
diff --git a/components/mus/public/interfaces/gpu.typemap b/components/mus/public/interfaces/gpu.typemap
new file mode 100644
index 0000000000000000000000000000000000000000..c720d113715daba0ac39d5ec1ba98e1ddb3e7759
--- /dev/null
+++ b/components/mus/public/interfaces/gpu.typemap
@@ -0,0 +1,14 @@
+// Copyright 2016 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.
+
+{
+  "c++": {
+    "mus.mojom.CommandBufferNamespace": {
+      "typename": "gpu::CommandBufferNamespace",
+      "headers": [
+        "gpu/command_buffer/common/constants.h"
+      ]
+    }
+  }
+}