Use OnceCallback for Mojo binding connection error handlers.

mojo/public/cpp/bindings/lib/associated_binding.cc

Index: mojo/public/cpp/bindings/lib/associated_binding.cc
diff --git a/mojo/public/cpp/bindings/lib/associated_binding.cc b/mojo/public/cpp/bindings/lib/associated_binding.cc
index 5f6db9a1e4ec55c8a03e8882e421c0505ae8b61d..6b1a3d273cc2b00e1229cba27f2d9cae58386722 100644
--- a/mojo/public/cpp/bindings/lib/associated_binding.cc
+++ b/mojo/public/cpp/bindings/lib/associated_binding.cc
@@ -28,15 +28,16 @@ void AssociatedBindingBase::CloseWithReason(uint32_t custom_reason,
 }
 
 void AssociatedBindingBase::set_connection_error_handler(
-    const base::Closure& error_handler) {
+    base::OnceClosure error_handler) {
   DCHECK(is_bound());
-  endpoint_client_->set_connection_error_handler(error_handler);
+  endpoint_client_->set_connection_error_handler(std::move(error_handler));
 }
 
 void AssociatedBindingBase::set_connection_error_with_reason_handler(
-    const ConnectionErrorWithReasonCallback& error_handler) {
+    ConnectionErrorWithReasonCallback error_handler) {
   DCHECK(is_bound());
-  endpoint_client_->set_connection_error_with_reason_handler(error_handler);
+  endpoint_client_->set_connection_error_with_reason_handler(
+      std::move(error_handler));
 }
 
 void AssociatedBindingBase::FlushForTesting() {