Fix summary handling of unresolved imports, exports, and parts.

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 544 matching lines @@
   @override
   ElementKind get kind => ElementKind.EXPORT;
 
   @override
   String get uri => actualElement.uri;
 
   @override
   int get uriEnd => actualElement.uriEnd;
 
   @override
-  bool get uriExists => actualElement.uriExists;
-
-  @override
   int get uriOffset => actualElement.uriOffset;
 }
 
 /**
  * A handle to a [FieldElement].
  */
 class FieldElementHandle extends PropertyInducingElementHandle
     implements FieldElement {
   /**
    * Initialize a newly created element handle to represent the element at the
@@ skipping 125 matching lines @@
   @override
   int get prefixOffset => actualElement.prefixOffset;
 
   @override
   String get uri => actualElement.uri;
 
   @override
   int get uriEnd => actualElement.uriEnd;
 
   @override
-  bool get uriExists => actualElement.uriExists;
-
-  @override
   int get uriOffset => actualElement.uriOffset;
 }
 
 /**
  * A handle to a [LabelElement].
  */
 class LabelElementHandle extends ElementHandle implements LabelElement {
   /**
    * Initialize a newly created element handle to represent the element at the
    * given [_location]. The [_resynthesizer] will be used to resynthesize the
@@ skipping 399 matching lines @@
 
   @override
   bool get isStatic => actualElement.isStatic;
 
   @override
   DartType get type => actualElement.type;
 
   @override
   DartObject computeConstantValue() => actualElement.computeConstantValue();
 }