[mojo] Implement pipe fusion API

mojo/public/cpp/bindings/interface_request.h

Index: mojo/public/cpp/bindings/interface_request.h
diff --git a/mojo/public/cpp/bindings/interface_request.h b/mojo/public/cpp/bindings/interface_request.h
index f67566d2d0ef76e2537eafe22b0e31f55f42a649..807cd5dc94c963d40cbc496a3c66151a74bbbcfe 100644
--- a/mojo/public/cpp/bindings/interface_request.h
+++ b/mojo/public/cpp/bindings/interface_request.h
@@ -117,6 +117,16 @@ InterfaceRequest<Interface> GetProxy(InterfacePtr<Interface>* ptr) {
   return MakeRequest<Interface>(std::move(pipe.handle1));
 }
 
+// Fuses an InterfaceRequest<T> endpoint with an InterfacePtrInfo<T> endpoint.
+// Returns |true| on success or |false| on failure.
+template <typename Interface>
+bool FuseInterface(InterfaceRequest<Interface> request,
+                   InterfacePtrInfo<Interface> proxy_info) {
+  MojoResult result = FuseMessagePipes(request.PassMessagePipe(),
+                                       proxy_info.PassHandle());
+  return result == MOJO_RESULT_OK;
+}
+
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_REQUEST_H_