Remove unused hasPromotedTypeVariable().

Change-Id: Ia8c40e6675ad9fc6eaeb02772cbe8a9b470b89d5
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/163541
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/lib/src/dart/element/type_demotion.dart b/pkg/analyzer/lib/src/dart/element/type_demotion.dart
index 37757e7..064cb13 100644
--- a/pkg/analyzer/lib/src/dart/element/type_demotion.dart
+++ b/pkg/analyzer/lib/src/dart/element/type_demotion.dart
@@ -5,7 +5,6 @@
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
-import 'package:analyzer/dart/element/type_visitor.dart';
 import 'package:analyzer/src/dart/element/replacement_visitor.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 
@@ -22,13 +21,6 @@
   }
 }
 
-/// Returns `true` if type contains a promoted type variable.
-bool hasPromotedTypeVariable(DartType type) {
-  return type.accept(
-    const _HasPromotedTypeVariableVisitor(),
-  );
-}
-
 /// Visitor that replaces all promoted type variables the type variable itself
 /// and/or replaces all legacy types with non-nullable types.
 ///
@@ -70,41 +62,3 @@
     );
   }
 }
-
-/// Visitor that returns `true` if a type contains a promoted type variable.
-class _HasPromotedTypeVariableVisitor extends UnifyingTypeVisitor<bool> {
-  const _HasPromotedTypeVariableVisitor();
-
-  @override
-  bool visitDartType(DartType type) => false;
-
-  @override
-  bool visitFunctionType(FunctionType type) {
-    if (type.returnType.accept(this)) {
-      return true;
-    }
-
-    for (var parameter in type.parameters) {
-      if (parameter.type.accept(this)) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  @override
-  bool visitInterfaceType(InterfaceType type) {
-    for (var typeArgument in type.typeArguments) {
-      if (typeArgument.accept(this)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  @override
-  bool visitTypeParameterType(TypeParameterType type) {
-    return (type as TypeParameterTypeImpl).promotedBound != null;
-  }
-}