[mojo] Add GenericInterface_ to interface class variants

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

Index: mojo/public/cpp/bindings/lib/interface_ptr_state.h
diff --git a/mojo/public/cpp/bindings/lib/interface_ptr_state.h b/mojo/public/cpp/bindings/lib/interface_ptr_state.h
index 8b8d6706fd47560848d3da0be0715c7cf886e389..d203031819b2a96fd6ce6724529d78b8788e4ce3 100644
--- a/mojo/public/cpp/bindings/lib/interface_ptr_state.h
+++ b/mojo/public/cpp/bindings/lib/interface_ptr_state.h
@@ -38,6 +38,8 @@ class InterfacePtrState;
 template <typename Interface>
 class InterfacePtrState<Interface, false> {
  public:
+  using GenericInterface = typename Interface::GenericInterface;
+
   InterfacePtrState()
       : proxy_(nullptr), router_(nullptr), waiter_(nullptr), version_(0u) {}
 
@@ -94,7 +96,8 @@ class InterfacePtrState<Interface, false> {
     swap(other->version_, version_);
   }
 
-  void Bind(InterfacePtrInfo<Interface> info, const MojoAsyncWaiter* waiter) {
+  void Bind(InterfacePtrInfo<GenericInterface> info,
+            const MojoAsyncWaiter* waiter) {
     DCHECK(!proxy_);
     DCHECK(!router_);
     DCHECK(!handle_.is_valid());
@@ -118,8 +121,8 @@ class InterfacePtrState<Interface, false> {
 
   // After this method is called, the object is in an invalid state and
   // shouldn't be reused.
-  InterfacePtrInfo<Interface> PassInterface() {
-    return InterfacePtrInfo<Interface>(
+  InterfacePtrInfo<GenericInterface> PassInterface() {
+    return InterfacePtrInfo<GenericInterface>(
         router_ ? router_->PassMessagePipe() : handle_.Pass(), version_);
   }
 
@@ -192,6 +195,8 @@ class InterfacePtrState<Interface, false> {
 template <typename Interface>
 class InterfacePtrState<Interface, true> {
  public:
+  using GenericInterface = typename Interface::GenericInterface;
+
   InterfacePtrState() : waiter_(nullptr), version_(0u) {}
 
   ~InterfacePtrState() {
@@ -248,7 +253,8 @@ class InterfacePtrState<Interface, true> {
     swap(other->version_, version_);
   }
 
-  void Bind(InterfacePtrInfo<Interface> info, const MojoAsyncWaiter* waiter) {
+  void Bind(InterfacePtrInfo<GenericInterface> info,
+            const MojoAsyncWaiter* waiter) {
     DCHECK(!router_);
     DCHECK(!endpoint_client_);
     DCHECK(!proxy_);
@@ -275,10 +281,10 @@ class InterfacePtrState<Interface, true> {
 
   // After this method is called, the object is in an invalid state and
   // shouldn't be reused.
-  InterfacePtrInfo<Interface> PassInterface() {
+  InterfacePtrInfo<GenericInterface> PassInterface() {
     endpoint_client_.reset();
     proxy_.reset();
-    return InterfacePtrInfo<Interface>(
+    return InterfacePtrInfo<GenericInterface>(
         router_ ? router_->PassMessagePipe() : handle_.Pass(), version_);
   }