Revert "Remove 'Element.docRange'."

pkg/analyzer/test/src/summary/summary_common.dart

 // Copyright (c) 2015, 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.test.src.summary.summary_common;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/scanner/reader.dart';
@@ skipping 268 matching lines @@
       UnlinkedDocumentationComment documentationComment, String text) {
     expect(documentationComment, isNotNull);
     int commentStart = text.indexOf('/*');
     expect(commentStart, isNot(-1));
     int commentEnd = text.indexOf('*/');
     expect(commentEnd, isNot(-1));
     commentEnd += 2;
     String expectedCommentText =
         text.substring(commentStart, commentEnd).replaceAll('\r\n', '\n');
     expect(documentationComment.text, expectedCommentText);
+    expect(documentationComment.offset, commentStart);
+    expect(documentationComment.length, commentEnd - commentStart);
   }
 
   /**
    * Verify that the given [typeRef] represents the type `dynamic`.
    */
   void checkDynamicTypeRef(EntityRef typeRef) {
     checkTypeRef(typeRef, null, null, 'dynamic');
   }
 
   /**
@@ skipping 10188 matching lines @@
 class _PrefixExpectation {
   final ReferenceKind kind;
   final String name;
   final String absoluteUri;
   final String relativeUri;
   final int numTypeParameters;
 
   _PrefixExpectation(this.kind, this.name,
       {this.absoluteUri, this.relativeUri, this.numTypeParameters: 0});
 }