Validation of `@protected` method invocations.

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

Index: pkg/analyzer/lib/dart/element/element.dart
diff --git a/pkg/analyzer/lib/dart/element/element.dart b/pkg/analyzer/lib/dart/element/element.dart
index d210229d602c3ce908b4f0432301af4c07fba5e5..f19579a42b221df7f5dba1966a5819fdd53c3d13 100644
--- a/pkg/analyzer/lib/dart/element/element.dart
+++ b/pkg/analyzer/lib/dart/element/element.dart
@@ -635,6 +635,11 @@ abstract class Element implements AnalysisTarget {
   bool get isPrivate;
 
   /**
+   * Return `true` if this element has an annotation of the form '@protected'.
+   */
+  bool get isProtected;
+
+  /**
    * Return `true` if this element is public. Public elements are visible within
    * any library that imports the library in which they are declared.
    */
@@ -808,6 +813,13 @@ abstract class ElementAnnotation implements ConstantEvaluationTarget {
    */
   bool get isOverride;
 
+
+  /**
+   * Return `true` if this annotation marks the associated member as being
+   * protected.
+   */
+  bool get isProtected;
+
   /**
    * Return `true` if this annotation marks the associated class as implementing
    * a proxy object.