DeCo. Remove a few isSynthetic references in tests.

For removed _assertNonSyntheticElementSelf invocations, the element
cannot be anything else than from a declaration, there is no isOriginX
to check.

Change-Id: I0df9b881c98ec329c9c2d14fb6c078fe7c5d0303
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/465961
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/test/src/summary/element_text.dart

@@ -329,11 +329,6 @@ class _Element2Writer extends _AbstractElementWriter {
     expect(flags.where((flag) => flag).length, 1);
   }
 
-  void _assertNonSyntheticElementSelf(Element element) {
-    expect(element.isSynthetic, isFalse);
-    expect(element.nonSynthetic, same(element));
-  }
-
   void _writeConstantInitializerExpression(String name, Expression expression) {
     if (_idMap.existingExpressionId(expression) case var id?) {
       _sink.writelnWithIndent('$name: $id');
@@ -1176,8 +1171,6 @@ class _Element2Writer extends _AbstractElementWriter {
       _writeElementList('setters', e, e.setters, _writeSetterElement);
       _writeElementList('methods', e, e.methods, _writeMethodElement);
     });
-
-    _assertNonSyntheticElementSelf(e);
   }
 
   void _writeInstanceFragment(InstanceFragmentImpl f) {
@@ -1699,8 +1692,6 @@ class _Element2Writer extends _AbstractElementWriter {
       // _writeAugmentationTarget(e);
       // _writeAugmentation(e);
     });
-
-    _assertNonSyntheticElementSelf(e);
   }
 
   void _writeTopLevelFunctionFragment(TopLevelFunctionFragmentImpl f) {
@@ -1906,8 +1897,6 @@ class _Element2Writer extends _AbstractElementWriter {
       // _writeAugmentationTarget(e);
       // _writeAugmentation(e);
     });
-
-    _assertNonSyntheticElementSelf(e);
   }
 
   void _writeTypeAliasFragment(TypeAliasFragmentImpl f) {
@@ -1985,8 +1974,6 @@ class _Element2Writer extends _AbstractElementWriter {
 
       _writeMetadata(e.metadata);
     });
-
-    _assertNonSyntheticElementSelf(e);
   }
 
   void _writeTypeParameterFragment(TypeParameterFragmentImpl f) {

pkg/analyzer/test/src/summary/resolved_ast_printer.dart

@@ -2125,7 +2125,6 @@ Expected parent: (${parent.runtimeType}) $parent
     _sink.writeIf(element.isPrivate, ' isPrivate');
     _sink.writeIf(element.isPublic, ' isPublic');
     _sink.writeIf(element.isStatic, ' isStatic');
-    _sink.writeIf(element.isSynthetic, ' isSynthetic');
   }
 
   static void _assertHasIdenticalElement<T>(List<T> elements, T expected) {