Fix summarization of unresolved annotations.

pkg/analyzer/lib/src/summary/summarize_elements.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 serialization.elements;
 
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 1320 matching lines @@
       EntityRefBuilder constructor;
       if (nameElement is ConstructorElement && name is PrefixedIdentifier) {
         assert(annotation.constructorName == null);
         constructor = serializeConstructorName(
             new TypeName(name.prefix, null)..type = nameElement.returnType,
             name.identifier);
       } else if (nameElement is TypeDefiningElement) {
         constructor = serializeConstructorName(
             new TypeName(annotation.name, null)..type = nameElement.type,
             annotation.constructorName);
+      } else if (nameElement == null) {
+        // Unresolved annotation.
+        if (name is PrefixedIdentifier && annotation.constructorName == null) {
+          constructor = serializeConstructorName(
+              new TypeName(name.prefix, null), name.identifier);
+        } else {
+          constructor = serializeConstructorName(
+              new TypeName(annotation.name, null), annotation.constructorName);
+        }
       } else {
         throw new StateError('Unexpected annotation nameElement type:'
             ' ${nameElement.runtimeType}');
       }
       serializeInstanceCreation(constructor, annotation.arguments);
     }
   }
 
   @override
   EntityRefBuilder serializeConstructorName(
@@ skipping 308 matching lines @@
       exportNames.add(new LinkedExportNameBuilder(
           name: name,
           dependency: serializeDependency(dependentLibrary),
           unit: unit,
           kind: kind));
     }
     pb.exportNames = exportNames;
     return pb;
   }
 }