Improve type information and minor clean up

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

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.generated.element_handle;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 449 matching lines @@
   @override
   accept(ElementVisitor visitor) => actualElement.accept(visitor);
 
   @override
   String computeDocumentationComment() => documentationComment;
 
   @override
   AstNode computeNode() => actualElement.computeNode();
 
   @override
-  Element getAncestor(Predicate<Element> predicate) =>
+  Element/*=E*/ getAncestor/*<E extends Element >*/(
+          Predicate<Element> predicate) =>
       actualElement.getAncestor(predicate);
 
   @override
   String getExtendedDisplayName(String shortName) =>
       actualElement.getExtendedDisplayName(shortName);
 
   @override
   bool isAccessibleIn(LibraryElement library) =>
       actualElement.isAccessibleIn(library);
 
@@ skipping 679 matching lines @@
 
   @override
   bool get isStatic => actualElement.isStatic;
 
   @override
   DartType get type => actualElement.type;
 
   @override
   DartObject computeConstantValue() => actualElement.computeConstantValue();
 }