Fix for PartDirective annotations while applying resynthesized element model.

pkg/analyzer/lib/src/generated/declaration_resolver.dart

 // Copyright (c) 2016, 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.declaration_resolver;
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ skipping 321 matching lines @@
     _walk(new ElementWalker.forExecutable(element, _enclosingUnit), () {
       super.visitMethodDeclaration(node);
     });
     _resolveMetadata(node, node.metadata, element);
     return null;
   }
 
   @override
   Object visitPartDirective(PartDirective node) {
     super.visitPartDirective(node);
-    _resolveAnnotations(
-        node, node.metadata, _enclosingUnit.getAnnotations(node.offset));
+    List<ElementAnnotation> annotations =
+        _enclosingUnit.getAnnotations(node.offset);
+    if (annotations.isEmpty && node.metadata.isNotEmpty) {
+      int index = (node.parent as CompilationUnit)
+          .directives
+          .where((directive) => directive is PartDirective)
+          .toList()
+          .indexOf(node);
+      annotations = _walker.element.library.parts[index].metadata;
+    }
+    _resolveAnnotations(node, node.metadata, annotations);
     return null;
   }
 
   @override
   Object visitPartOfDirective(PartOfDirective node) {
     node.element = _enclosingUnit.library;
     return super.visitPartOfDirective(node);
   }
 
   @override
@@ skipping 368 matching lines @@
 class _ElementMismatchException extends AnalysisException {
   /**
    * Creates an exception to refer to the given [compilationUnit], [element],
    * and [cause].
    */
   _ElementMismatchException(
       CompilationUnitElement compilationUnit, Element element,
       [CaughtException cause = null])
       : super('Element mismatch in $compilationUnit at $element', cause);
 }