[mojo] Add GenericInterface_ to interface class variants

This is used to identify pure non-variant interface
definitions for uses relevant to InterfaceRequest.

e.g. one could do

  variant1::FooPtr foo;
  GetProxy(&foo)

and GetProxy will return an InterfaceRequest<generic::Foo>.

Part of a series of changes to support custom mojom serialization:

  1. https://codereview.chromium.org/1515423002
  2. https://codereview.chromium.org/1517043004
  3. This CL
  4. https://codereview.chromium.org/1520153002
  5. https://codereview.chromium.org/1524613002
  6. https://codereview.chromium.org/1526533002
  7. https://codereview.chromium.org/1524703002

BUG=569669
TBR=sky@chromium.org for mojo/common
TBR=piman@chromium.org for content/gpu

Review URL: https://codereview.chromium.org/1524693002

Cr-Commit-Position: refs/heads/master@{#365708}

1 files changed, 7 insertions, 2 deletions

diff --git a/mojo/common/weak_binding_set.h b/mojo/common/weak_binding_set.h
index 85c8031..c3736ff 100644
--- a/mojo/common/weak_binding_set.h
+++ b/mojo/common/weak_binding_set.h
@@ -21,6 +21,8 @@ class WeakBinding;
 template <typename Interface>
 class WeakBindingSet {
  public:
+  using GenericInterface = typename Interface::GenericInterface;
+
   WeakBindingSet() {}
   ~WeakBindingSet() { CloseAllBindings(); }
 
@@ -28,7 +30,8 @@ class WeakBindingSet {
     error_handler_ = error_handler;
   }
 
-  void AddBinding(Interface* impl, InterfaceRequest<Interface> request) {
+  void AddBinding(Interface* impl,
+                  InterfaceRequest<GenericInterface> request) {
     auto binding = new WeakBinding<Interface>(impl, request.Pass());
     binding->set_connection_error_handler([this]() { OnConnectionError(); });
     bindings_.push_back(binding->GetWeakPtr());
@@ -68,7 +71,9 @@ class WeakBindingSet {
 template <typename Interface>
 class WeakBinding {
  public:
-  WeakBinding(Interface* impl, InterfaceRequest<Interface> request)
+  using GenericInterface = typename Interface::GenericInterface;
+
+  WeakBinding(Interface* impl, InterfaceRequest<GenericInterface> request)
       : binding_(impl, request.Pass()),
         weak_ptr_factory_(this) {
     binding_.set_connection_error_handler([this]() { OnConnectionError(); });