mojo: Allow circular dependencies between structs

mojo/public/cpp/bindings/lib/bindings_internal.h

Index: mojo/public/cpp/bindings/lib/bindings_internal.h
diff --git a/mojo/public/cpp/bindings/lib/bindings_internal.h b/mojo/public/cpp/bindings/lib/bindings_internal.h
index 8650191cfaeadb97fa7b6675afef20631551a809..df3c620f084d2d1558e263b271b16f99a28cc635 100644
--- a/mojo/public/cpp/bindings/lib/bindings_internal.h
+++ b/mojo/public/cpp/bindings/lib/bindings_internal.h
@@ -6,6 +6,7 @@
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_INTERNAL_H_
 
 #include "mojo/public/cpp/bindings/lib/template_util.h"
+#include "mojo/public/cpp/bindings/struct_ptr.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace mojo {
@@ -81,6 +82,14 @@ struct WrapperTraits<ScopedHandleBase<H>, true> {
   typedef H DataType;
 };
 template <typename S>
+struct WrapperTraits<StructPtr<S>, true> {
+  typedef typename S::Data_* DataType;
+};
+template <typename S>
+struct WrapperTraits<InlinedStructPtr<S>, true> {
+  typedef typename S::Data_* DataType;
+};
+template <typename S>
 struct WrapperTraits<S, true> {
   typedef typename S::Data_* DataType;
 };