Add associated interfaces & bindings.

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 adc4e7e809e91d79e9bfdc4d95acdbe0edb95c93..3858330aecf242a6675b19d7fd9dd6d23a582e50 100644
--- a/mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom
+++ b/mojo/public/interfaces/bindings/tests/test_associated_interfaces.mojom
@@ -45,6 +45,11 @@ interface IntegerSenderConnection {
   AsyncGetSender() => (associated IntegerSender sender);
 };
 
+interface IntegerSenderConnectionAtBothEnds {
+  GetSender(associated IntegerSender& sender);
+  SetSender(associated IntegerSender sender) => (int32 value);
+};
+
 interface AssociatedPingProvider {
   GetPing(associated PingService& request);
 };