Mojo C++ bindings: remove some usage of AssociatedGroup from user code.

chrome/browser/ui/ash/cast_config_client_media_router.cc

Index: chrome/browser/ui/ash/cast_config_client_media_router.cc
diff --git a/chrome/browser/ui/ash/cast_config_client_media_router.cc b/chrome/browser/ui/ash/cast_config_client_media_router.cc
index 26e78476ba69fc77552a6ea3d0bf998139e4dc9f..920f4cd71fc88558ec877bb26322d05b448d7625 100644
--- a/chrome/browser/ui/ash/cast_config_client_media_router.cc
+++ b/chrome/browser/ui/ash/cast_config_client_media_router.cc
@@ -154,7 +154,7 @@ CastConfigClientMediaRouter::CastConfigClientMediaRouter() : binding_(this) {
 
   // Register this object as the client interface implementation.
   ash::mojom::CastConfigClientAssociatedPtrInfo ptr_info;
-  binding_.Bind(&ptr_info, cast_config_.associated_group());
+  binding_.Bind(&ptr_info);
   cast_config_->SetClient(std::move(ptr_info));
 }