[mojo] Add GenericInterface_ to interface class variants

mojo/public/cpp/bindings/associated_group.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_GROUP_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_GROUP_H_
 
 #include "base/memory/ref_counted.h"
 #include "mojo/public/cpp/bindings/associated_interface_ptr_info.h"
 #include "mojo/public/cpp/bindings/associated_interface_request.h"
@@ skipping 26 matching lines @@
   // remote side of the message pipe.
   //
   // NOTE: If |config| is |WILL_PASS_REQUEST|, you will want to bind |ptr_info|
   // to a local AssociatedInterfacePtr to make calls. However, there is one
   // restriction: the pointer should NOT be used to make calls before |request|
   // is sent. Violating that will cause the message pipe to be closed. On the
   // other hand, as soon as |request| is sent, the pointer is usable. There is
   // no need to wait until |request| is bound to an implementation at the remote
   // side.
   template <typename T>
-  void CreateAssociatedInterface(AssociatedInterfaceConfig config,
-                                 AssociatedInterfacePtrInfo<T>* ptr_info,
-                                 AssociatedInterfaceRequest<T>* request) {
+  void CreateAssociatedInterface(
+      AssociatedInterfaceConfig config,
+      AssociatedInterfacePtrInfo<T>* ptr_info,

[yzshen1, 2015/12/14 23:58:26]

ptr_info should use the same type as the request, right?

InterfacePtrInfo <-> InterfacePtr is exactly the same relationship as
InterfaceRequest <-> Binding. So we probably don't want |ptr_info| to use a
"variant" type.

Therefore, it seems correct to leave this method untouched. WDYT?

+      AssociatedInterfaceRequest<typename T::GenericInterface>* request) {
     internal::ScopedInterfaceEndpointHandle local;
     internal::ScopedInterfaceEndpointHandle remote;
     CreateEndpointHandlePair(&local, &remote);
 
     if (!local.is_valid() || !remote.is_valid()) {
       *ptr_info = AssociatedInterfacePtrInfo<T>();
-      *request = AssociatedInterfaceRequest<T>();
+      *request = AssociatedInterfaceRequest<typename T::GenericInterface>();
       return;
     }
 
     if (config == WILL_PASS_PTR) {
       internal::AssociatedInterfacePtrInfoHelper::SetHandle(ptr_info,
                                                             remote.Pass());
       // The implementation is local, therefore set the version according to
       // the interface definition that this code is built against.
       ptr_info->set_version(T::Version_);
       internal::AssociatedInterfaceRequestHelper::SetHandle(request,
@@ skipping 15 matching lines @@
   void CreateEndpointHandlePair(
       internal::ScopedInterfaceEndpointHandle* local_endpoint,
       internal::ScopedInterfaceEndpointHandle* remote_endpoint);
 
   scoped_refptr<internal::MultiplexRouter> router_;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_GROUP_H_