Replace using MockSdk with FolderBasedDartSdk + summaries in AbstractContextTest(s).

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

Index: pkg/analysis_server/lib/src/services/correction/fix_internal.dart
diff --git a/pkg/analysis_server/lib/src/services/correction/fix_internal.dart b/pkg/analysis_server/lib/src/services/correction/fix_internal.dart
index f0b353fa6ebe28abbfca0d4f79470f71a8927796..efec5eeb46118204359679ef9dace81dfcec3234 100644
--- a/pkg/analysis_server/lib/src/services/correction/fix_internal.dart
+++ b/pkg/analysis_server/lib/src/services/correction/fix_internal.dart
@@ -1541,7 +1541,7 @@ class FixProcessor {
         }
         // prepare LibraryElement
         LibraryElement libraryElement =
-            context.getResult(librarySource, LIBRARY_ELEMENT1);
+            context.computeResult(librarySource, LIBRARY_ELEMENT1);
         if (libraryElement == null) {
           continue;
         }