Move Modifier out of the public API

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 509dd4c1b5f544b8a7e16f57469d736a093d0829..e319acf7cea9e5ca65e1a4f22ed67d7923c7dda9 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -3660,6 +3660,148 @@ class MethodElementImpl extends ExecutableElementImpl implements MethodElement {
 }
 
 /**
+ * The enumeration `Modifier` defines constants for all of the modifiers defined
+ * by the Dart language and for a few additional flags that are useful.
+ *
+ * Clients may not extend, implement or mix-in this class.
+ */
+class Modifier extends Enum<Modifier> {
+  /**
+   * Indicates that the modifier 'abstract' was applied to the element.
+   */
+  static const Modifier ABSTRACT = const Modifier('ABSTRACT', 0);
+
+  /**
+   * Indicates that an executable element has a body marked as being
+   * asynchronous.
+   */
+  static const Modifier ASYNCHRONOUS = const Modifier('ASYNCHRONOUS', 1);
+
+  /**
+   * Indicates that the modifier 'const' was applied to the element.
+   */
+  static const Modifier CONST = const Modifier('CONST', 2);
+
+  /**
+   * Indicates that the import element represents a deferred library.
+   */
+  static const Modifier DEFERRED = const Modifier('DEFERRED', 3);
+
+  /**
+   * Indicates that a class element was defined by an enum declaration.
+   */
+  static const Modifier ENUM = const Modifier('ENUM', 4);
+
+  /**
+   * Indicates that a class element was defined by an enum declaration.
+   */
+  static const Modifier EXTERNAL = const Modifier('EXTERNAL', 5);
+
+  /**
+   * Indicates that the modifier 'factory' was applied to the element.
+   */
+  static const Modifier FACTORY = const Modifier('FACTORY', 6);
+
+  /**
+   * Indicates that the modifier 'final' was applied to the element.
+   */
+  static const Modifier FINAL = const Modifier('FINAL', 7);
+
+  /**
+   * Indicates that an executable element has a body marked as being a
+   * generator.
+   */
+  static const Modifier GENERATOR = const Modifier('GENERATOR', 8);
+
+  /**
+   * Indicates that the pseudo-modifier 'get' was applied to the element.
+   */
+  static const Modifier GETTER = const Modifier('GETTER', 9);
+
+  /**
+   * A flag used for libraries indicating that the defining compilation unit
+   * contains at least one import directive whose URI uses the "dart-ext"
+   * scheme.
+   */
+  static const Modifier HAS_EXT_URI = const Modifier('HAS_EXT_URI', 10);
+
+  /**
+   * Indicates that the associated element did not have an explicit type
+   * associated with it. If the element is an [ExecutableElement], then the
+   * type being referred to is the return type.
+   */
+  static const Modifier IMPLICIT_TYPE = const Modifier('IMPLICIT_TYPE', 11);
+
+  /**
+   * Indicates that a class is a mixin application.
+   */
+  static const Modifier MIXIN_APPLICATION =
+      const Modifier('MIXIN_APPLICATION', 12);
+
+  /**
+   * Indicates that the value of a parameter or local variable might be mutated
+   * within the context.
+   */
+  static const Modifier POTENTIALLY_MUTATED_IN_CONTEXT =
+      const Modifier('POTENTIALLY_MUTATED_IN_CONTEXT', 13);
+
+  /**
+   * Indicates that the value of a parameter or local variable might be mutated
+   * within the scope.
+   */
+  static const Modifier POTENTIALLY_MUTATED_IN_SCOPE =
+      const Modifier('POTENTIALLY_MUTATED_IN_SCOPE', 14);
+
+  /**
+   * Indicates that a class contains an explicit reference to 'super'.
+   */
+  static const Modifier REFERENCES_SUPER =
+      const Modifier('REFERENCES_SUPER', 15);
+
+  /**
+   * Indicates that the pseudo-modifier 'set' was applied to the element.
+   */
+  static const Modifier SETTER = const Modifier('SETTER', 16);
+
+  /**
+   * Indicates that the modifier 'static' was applied to the element.
+   */
+  static const Modifier STATIC = const Modifier('STATIC', 17);
+
+  /**
+   * Indicates that the element does not appear in the source code but was
+   * implicitly created. For example, if a class does not define any
+   * constructors, an implicit zero-argument constructor will be created and it
+   * will be marked as being synthetic.
+   */
+  static const Modifier SYNTHETIC = const Modifier('SYNTHETIC', 18);
+
+  static const List<Modifier> values = const [
+    ABSTRACT,
+    ASYNCHRONOUS,
+    CONST,
+    DEFERRED,
+    ENUM,
+    EXTERNAL,
+    FACTORY,
+    FINAL,
+    GENERATOR,
+    GETTER,
+    HAS_EXT_URI,
+    IMPLICIT_TYPE,
+    MIXIN_APPLICATION,
+    POTENTIALLY_MUTATED_IN_CONTEXT,
+    POTENTIALLY_MUTATED_IN_SCOPE,
+    REFERENCES_SUPER,
+    SETTER,
+    STATIC,
+    SYNTHETIC
+  ];
+
+  const Modifier(String name, int ordinal) : super(name, ordinal);
+}
+
+/**
  * A concrete implementation of a [MultiplyDefinedElement].
  */
 class MultiplyDefinedElementImpl implements MultiplyDefinedElement {