Issue 18926. Rename refactoring for labels.

pkg/analysis_server/lib/src/services/refactoring/naming_conventions.dart

Index: pkg/analysis_server/lib/src/services/refactoring/naming_conventions.dart
diff --git a/pkg/analysis_server/lib/src/services/refactoring/naming_conventions.dart b/pkg/analysis_server/lib/src/services/refactoring/naming_conventions.dart
index 2e815fa25b51deaac1faed9aa4fa5b837d01f16e..8e3539f16a6d754dd12f4554e97fd251a668c533 100644
--- a/pkg/analysis_server/lib/src/services/refactoring/naming_conventions.dart
+++ b/pkg/analysis_server/lib/src/services/refactoring/naming_conventions.dart
@@ -114,6 +114,16 @@ RefactoringStatus validateImportPrefixName(String name) {
  *   WARNING if the name is discouraged;
  *   ERROR if the name is illegal.
  */
+RefactoringStatus validateLabelName(String name) {
+  return _validateLowerCamelCase(name, "Label");
+}
+
+/**
+ * Returns the [RefactoringStatus] with severity:
+ *   OK if the name is valid;
+ *   WARNING if the name is discouraged;
+ *   ERROR if the name is illegal.
+ */
 RefactoringStatus validateLibraryName(String name) {
   // null
   if (name == null) {