Revert "Flush AST results for source outside of the analysis roots."

pkg/analyzer/test/src/task/incremental_element_builder_test.dart

Index: pkg/analyzer/test/src/task/incremental_element_builder_test.dart
diff --git a/pkg/analyzer/test/src/task/incremental_element_builder_test.dart b/pkg/analyzer/test/src/task/incremental_element_builder_test.dart
index f5668ff660f75b5e3fee263c1883eb4ec83c6e3b..56f174e4f773c459f535c5dc1930d1846882f5a4 100644
--- a/pkg/analyzer/test/src/task/incremental_element_builder_test.dart
+++ b/pkg/analyzer/test/src/task/incremental_element_builder_test.dart
@@ -2001,7 +2001,7 @@ main() {
       unitDelta = builder.unitDelta;
       expect(newUnit.element, unitElement);
       // Flush all tokens, ASTs and elements.
-      context.analysisCache.flush((target) => true, (target, result) {
+      context.analysisCache.flush((target, result) {
         return result == TOKEN_STREAM ||
             result == PARSED_UNIT ||
             RESOLVED_UNIT_RESULTS.contains(result) ||