Mojo C++ bindings: introduce public associated-interface-related types.

mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom

Index: mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom
diff --git a/mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom b/mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom
index d81a9193bc23add1b3f794b56ceab9c8e8d7207b..62ff7a7cc876cc1da3a0358e9779950c075cd602 100644
--- a/mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom
+++ b/mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom
@@ -28,3 +28,13 @@ interface InterfacePassesAssociated {
   PassUnion(UnionContainsAssociated foo_union) =>
            (UnionContainsAssociated foo_union);
 };
+
+interface IntegerSender {
+  Echo(int32 value) => (int32 value);
+  Send(int32 value);
+};
+
+interface IntegerSenderConnection {
+  GetSender(associated IntegerSender& sender);
+  AsyncGetSender() => (associated IntegerSender sender);
+};