C bindings pt3: Type table definitions and barebones files to get generated code to compile.

mojo/public/c/bindings/interface.h

+// 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.
+
+#ifndef MOJO_PUBLIC_C_BINDINGS_INTERFACE_H_
+#define MOJO_PUBLIC_C_BINDINGS_INTERFACE_H_
+
+#include <stdint.h>
+
+#include "mojo/public/c/system/handle.h"
+#include "mojo/public/c/system/macros.h"
+
+MOJO_BEGIN_EXTERN_C
+
+// |MojomInterfaceData| represents a handle to an interface; in particular, this
+// is the client side of the interface where messages are sent and responses are
+// received.
+struct MojomInterfaceData {
+  MojoHandle handle;

[viettrungluu, 2016/06/17 20:37:19]

Strictly speaking, isn't this either a handle or an index?

[vardhan, 2016/06/21 16:07:36]

true -- i'll add a comment.  I was thinking about making it a union, but it's
still awkard to use since an invalid encoded handle offset is '-1' of the
MojoHandle type (which is currently uint32_t MAX), so we would have to continue
using the |handle| value as MojoHandle..

+  uint32_t version;
+};
+MOJO_STATIC_ASSERT(sizeof(struct MojomInterfaceData) == 8,
+                   "struct MojomInterfaceData must be 8 bytes.");
+
+MOJO_END_EXTERN_C
+
+#endif  // MOJO_PUBLIC_C_BINDINGS_INTERFACE_H_