Rust: Polish off communication across Mojom interfaces

mojo/public/rust/tests/encoding.rs

Index: mojo/public/rust/tests/encoding.rs
diff --git a/mojo/public/rust/tests/encoding.rs b/mojo/public/rust/tests/encoding.rs
index 5246203728665f90ce8d3c3b6498b5bda4c42a91..88b13347674581a2455f0eeb6fd568be10b0855a 100644
--- a/mojo/public/rust/tests/encoding.rs
+++ b/mojo/public/rust/tests/encoding.rs
@@ -672,4 +672,34 @@ encoding_tests! {
             }
         }
     }
+    integration_intf_rqst_mthd0_good {
+        MessageHeader => {
+            |header: MessageHeader| {
+                assert_eq!(header.version, 1);
+                assert_eq!(header.name, 0);
+                assert_eq!(header.flags, 1);
+                assert_eq!(header.request_id, 7);
+            }
+        },
+        IntegrationTestInterfaceMethod0Request => {
+            |payload: &IntegrationTestInterfaceMethod0Request| {
+                assert_eq!(payload.param0.a, -1);
+            }
+        }
+    }
+    integration_intf_resp_mthd0_good {
+        MessageHeader => {
+            |header: MessageHeader| {
+                assert_eq!(header.version, 1);
+                assert_eq!(header.name, 0);
+                assert_eq!(header.flags, 2);
+                assert_eq!(header.request_id, 1);
+            }
+        },
+        IntegrationTestInterfaceMethod0Response => {
+            |payload: &IntegrationTestInterfaceMethod0Response| {
+                assert_eq!(payload.param0, vec![0]);
+            }
+        }
+    }
 }