remove unused locals/members/test functions

pkg/analyzer/test/src/task/strong/strong_test_helper.dart

Index: pkg/analyzer/test/src/task/strong/strong_test_helper.dart
diff --git a/pkg/analyzer/test/src/task/strong/strong_test_helper.dart b/pkg/analyzer/test/src/task/strong/strong_test_helper.dart
index e28a01e68afe92d80a45998e238b2ec47f4eb47a..83c047773ff09752d838d8458d010ae5df01b01e 100644
--- a/pkg/analyzer/test/src/task/strong/strong_test_helper.dart
+++ b/pkg/analyzer/test/src/task/strong/strong_test_helper.dart
@@ -46,12 +46,6 @@ void checkFile(String content) {
   check();
 }
 
-/// Adds [files] using [addFiles] and calls [check].
-void checkFiles(Map<String, String> files) {
-  addFiles(files);
-  check();
-}
-
 /// Adds a file to check. The file should contain:
 ///
 ///   * all expected failures are listed in the source code using comments