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

mojo/public/c/bindings/string.h

Index: mojo/public/c/bindings/string.h
diff --git a/mojo/public/c/bindings/string.h b/mojo/public/c/bindings/string.h
new file mode 100644
index 0000000000000000000000000000000000000000..24784bfa3adc9f5f8774dc9efdabe999bfaa4f91
--- /dev/null
+++ b/mojo/public/c/bindings/string.h
@@ -0,0 +1,27 @@
+// 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_STRING_H_
+#define MOJO_PUBLIC_C_BINDINGS_STRING_H_
+
+#include "mojo/public/c/bindings/array.h"
+#include "mojo/public/c/bindings/buffer.h"
+
+// A mojom string is a mojom array of UTF8 chars that need not be
+// null-terminated.
+struct MojomStringHeader {
+  struct MojomArrayHeader chars;
+};
+MOJO_STATIC_ASSERT(sizeof(struct MojomStringHeader) ==
+                       sizeof(struct MojomArrayHeader),
+                   "MojomStringHeader must be just a MojomArrayHeader.");
+
+union MojomStringHeaderPtr {
+  struct MojomStringHeader* ptr;
+  uint64_t offset;
+};
+MOJO_STATIC_ASSERT(sizeof(union MojomStringHeaderPtr) == 8,
+                   "MojomStringHeaderPtr must be 8 byes.");
+
+#endif  // MOJO_PUBLIC_C_BINDINGS_STRING_H_