Fix @protected checks to play nice with generic supers (linter#257).

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 2a141a60268d7cb81f04cf573c09c602c66f989c..9054cabe99869f5ada4ffebaf905bd9675017c72 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -982,9 +982,17 @@ class BestPracticesVerifier extends RecursiveAstVisitor<Object> {
 //    return false;
 //  }
 
-  bool _hasTypeOrSuperType(ClassElement element, InterfaceType type) =>
-      element != null &&
-      (element.type == type || element.allSupertypes.contains(type));
+  bool _hasTypeOrSuperType(ClassElement element, InterfaceType type) {
+    if (element == null) {
+      return false;
+    }
+    if (element.type == type) {

[Brian Wilkerson, 2016/06/06 20:23:00]

I don't understand why this wouldn't be "element == typeElement". I don't know
that it's possible for the 'type' to be something different from 'element.type',
but I think the result would be wrong if it happened.

+      return true;
+    }
+    ClassElement typeElement = type.element;
+    return element.allSupertypes
+        .any((InterfaceType t) => t.element == typeElement);
+  }
 
   /**
    * Given a parenthesized expression, this returns the parent (or recursively grand-parent) of the