[mojo] Add GenericInterface_ to interface class variants

mojo/public/cpp/bindings/associated_interface_ptr.h

Index: mojo/public/cpp/bindings/associated_interface_ptr.h
diff --git a/mojo/public/cpp/bindings/associated_interface_ptr.h b/mojo/public/cpp/bindings/associated_interface_ptr.h
index 15c12ce7ec9a38d55992dfd95606d1823dd298ff..8c2e6862abf50cc05c3f002e46c3626891b7beab 100644
--- a/mojo/public/cpp/bindings/associated_interface_ptr.h
+++ b/mojo/public/cpp/bindings/associated_interface_ptr.h
@@ -22,6 +22,8 @@ class AssociatedInterfacePtr {
   DISALLOW_COPY_AND_ASSIGN_WITH_MOVE_FOR_BIND(AssociatedInterfacePtr)
 
  public:
+  using GenericInterface = typename Interface::GenericInterface;
+
   // Constructs an unbound AssociatedInterfacePtr.
   AssociatedInterfacePtr() {}
   AssociatedInterfacePtr(decltype(nullptr)) {}
@@ -52,7 +54,7 @@ class AssociatedInterfacePtr {
   // NOTE: Please see the comments of
   // AssociatedGroup.CreateAssociatedInterface() about when you can use this
   // object to make calls.
-  void Bind(AssociatedInterfacePtrInfo<Interface> info) {
+  void Bind(AssociatedInterfacePtrInfo<GenericInterface> info) {
     reset();
 
     bool is_local =
@@ -120,7 +122,7 @@ class AssociatedInterfacePtr {
   // It is an error to call PassInterface() while there are pending responses.
   // TODO: fix this restriction, it's not always obvious when there is a
   // pending response.
-  AssociatedInterfacePtrInfo<Interface> PassInterface() {
+  AssociatedInterfacePtrInfo<GenericInterface> PassInterface() {
     DCHECK(!internal_state_.has_pending_callbacks());
     State state;
     internal_state_.Swap(&state);