Eliminate dependencies on pkg/front_end.

pkg/analyzer_plugin/lib/src/utilities/completion/suggestion_builder.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart'
     hide Element, ElementKind;
 import 'package:analyzer_plugin/src/utilities/documentation.dart';
 import 'package:analyzer_plugin/utilities/analyzer_converter.dart';
 import 'package:analyzer_plugin/utilities/completion/relevance.dart';
 import 'package:analyzer_plugin/utilities/completion/suggestion_builder.dart';
-import 'package:front_end/src/base/source.dart' show Source;
-import 'package:front_end/src/base/uri_kind.dart';
+import 'package:analyzer/src/generated/source.dart' show Source, UriKind;
 
 /**
  * An object used to build code completion suggestions for Dart code.
  */
 class SuggestionBuilderImpl implements SuggestionBuilder {
   /**
    * The resource provider used to access the file system.
    */
   final ResourceProvider resourceProvider;
 
@@ skipping 157 matching lines @@
     } else if (element is VariableElement) {
       DartType type = element.type;
       return type != null ? type.displayName : 'dynamic';
     } else if (element is FunctionTypeAliasElement) {
       return element.returnType.toString();
     } else {
       return null;
     }
   }
 }