[mojo] Add GenericInterface_ to interface class variants

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

Index: mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
diff --git a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
index 2a111eaf190e4e7927b9978c126f5353d2feb930..00f2de5fb5846742f5c86c7c2d808ff61a57fcff 100644
--- a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
+++ b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
@@ -24,6 +24,8 @@ namespace internal {
 template <typename Interface>
 class AssociatedInterfacePtrState {
  public:
+  using GenericInterface = typename Interface::GenericInterface;
+
   AssociatedInterfacePtrState() : version_(0u) {}
 
   ~AssociatedInterfacePtrState() {
@@ -69,7 +71,7 @@ class AssociatedInterfacePtrState {
     swap(other->version_, version_);
   }
 
-  void Bind(AssociatedInterfacePtrInfo<Interface> info) {
+  void Bind(AssociatedInterfacePtrInfo<GenericInterface> info) {
     DCHECK(!endpoint_client_);
     DCHECK(!proxy_);
     DCHECK_EQ(0u, version_);
@@ -85,12 +87,12 @@ class AssociatedInterfacePtrState {
 
   // After this method is called, the object is in an invalid state and
   // shouldn't be reused.
-  AssociatedInterfacePtrInfo<Interface> PassInterface() {
+  AssociatedInterfacePtrInfo<GenericInterface> PassInterface() {
     ScopedInterfaceEndpointHandle handle = endpoint_client_->PassHandle();
     endpoint_client_.reset();
     proxy_.reset();
 
-    AssociatedInterfacePtrInfo<Interface> result;
+    AssociatedInterfacePtrInfo<GenericInterface> result;
     result.set_version(version_);
     AssociatedInterfacePtrInfoHelper::SetHandle(&result, handle.Pass());
     return result.Pass();