Reduce boilerplate needed to configure mojo::Binding

mash/browser_driver/browser_driver_application_delegate.cc

Index: mash/browser_driver/browser_driver_application_delegate.cc
diff --git a/mash/browser_driver/browser_driver_application_delegate.cc b/mash/browser_driver/browser_driver_application_delegate.cc
index ebd41dc01ddd1980b97798bde6c216b8f506c5c9..cc580b1149be967b8ac37119fd467b1cc1244d82 100644
--- a/mash/browser_driver/browser_driver_application_delegate.cc
+++ b/mash/browser_driver/browser_driver_application_delegate.cc
@@ -86,14 +86,12 @@ void BrowserDriverApplicationDelegate::AddAccelerators() {
 
   if (binding_.is_bound())
     binding_.Unbind();
-  mus::mojom::AcceleratorHandlerPtr handler;
-  binding_.Bind(GetProxy(&handler));
   // If the window manager restarts, the handler pipe will close and we'll need
   // to re-add our accelerators when the window manager comes back up.
   binding_.set_connection_error_handler(
       base::Bind(&BrowserDriverApplicationDelegate::AddAccelerators,
                  base::Unretained(this)));
-  registrar->SetHandler(std::move(handler));
+  registrar->SetHandler(binding_.CreateInterfacePtrAndBind());
 
   for (const AcceleratorSpec& spec : g_spec) {
     registrar->AddAccelerator(