In summaries, don't drop unsafe prefixes.

pkg/analyzer/lib/src/summary/resynthesize.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 summary_resynthesizer;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 422 matching lines @@
           _pushMap(null);
           break;
         case UnlinkedConstOperation.makeTypedMap:
           TypeName keyType = _newTypeName();
           TypeName valueType = _newTypeName();
           _pushMap(AstFactory.typeArgumentList(<TypeName>[keyType, valueType]));
           break;
         case UnlinkedConstOperation.pushReference:
           EntityRef ref = uc.references[refPtr++];
           _ReferenceInfo info = resynthesizer.referenceInfos[ref.reference];
-          SimpleIdentifier node = AstFactory.identifier3(info.name);
-          node.staticElement = info.element;
-          _push(node);
+          if (info.enclosing != null &&
+              info.enclosing.element != null &&
+              info.enclosing.element is! ClassElement) {
+            SimpleIdentifier prefix = AstFactory.identifier3(
+                info.enclosing.name)..staticElement = info.enclosing.element;
+            SimpleIdentifier name = AstFactory.identifier3(info.name)
+              ..staticElement = info.element;
+            PrefixedIdentifier node = AstFactory.identifier(prefix, name);
+            _push(node);
+          } else {
+            SimpleIdentifier node = AstFactory.identifier3(info.name);
+            node.staticElement = info.element;
+            _push(node);
+          }
           break;
         case UnlinkedConstOperation.invokeConstructor:
           _pushInstanceCreation();
           break;
         case UnlinkedConstOperation.length:
           Expression target = _pop();
           SimpleIdentifier property = AstFactory.identifier3('length');
           property.staticElement =
               resynthesizer._buildStringLengthPropertyAccessorElement();
           _push(AstFactory.propertyAccess(target, property));
@@ skipping 1965 matching lines @@
     List<DartType> typeArguments = const <DartType>[];
     if (numTypeArguments != 0) {
       typeArguments = <DartType>[];
       for (int i = 0; i < numTypeArguments; i++) {
         typeArguments.add(getTypeArgument(i));
       }
     }
     return typeArguments;
   }
 }