Perform InterfaceProviderSpec intersection in the ServiceManager

services/service_manager/public/interfaces/service.mojom

Index: services/service_manager/public/interfaces/service.mojom
diff --git a/services/service_manager/public/interfaces/service.mojom b/services/service_manager/public/interfaces/service.mojom
index e5f8d681928bc6b713d660a1647405f0872eca47..207da8cd96e2534cc12a84dc579459160005593f 100644
--- a/services/service_manager/public/interfaces/service.mojom
+++ b/services/service_manager/public/interfaces/service.mojom
@@ -67,4 +67,32 @@ interface Service {
   //    seek to bind interface implementations exported by the target.
   //
   OnConnect(ServiceInfo source_info, InterfaceProvider&? interfaces) => ();
+
+  // Called when a request to bind an interface is received from another
+  // ("source") service. This is the result of that service calling
+  // BindInterface() on a Connector. By the time this method is called, the
+  // service manager has already completed a policy check to determine that this
+  // interface can be bound.
+  //
+  // The Service must respond to acknowledge receipt of the request.
+  //
+  // Parameters:
+  //
+  //  source_info
+  //    Contains the source identity and interface provider specs.
+  //
+  //  interface_name
+  //    The name of the interface to be bound.
+  //
+  //  interface_pipe
+  //    The message pipe to bind the interface implementation to.
+  //
+  // TODO(beng): It occurs to me that |source_info| leaks all metadata about
+  //             the source's capability requirements to the target. This seems
+  //             undesirable. The metadata supplied here should be germane to
+  //             fulfilling this request and no more.
+  // TODO(beng): This should replace OnConnect().
+  OnBindInterface(ServiceInfo source_info,
+                  string interface_name,
+                  handle<message_pipe> interface_pipe) => ();
 };