Process handled exports correctly.

tests/compiler/dart2js/reexport_handled_test.dart

+// Copyright (c) 2013, 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 reexport_handled_test;
+
+import 'dart:uri';
+import 'mock_compiler.dart';
+import '../../../sdk/lib/_internal/compiler/implementation/elements/elements.dart'
+    show Element,
+         LibraryElement;
+
+final exportingLibraryUri = new Uri('exporting.dart');
+const String EXPORTING_LIBRARY_SOURCE = '''
+library exporting;
+var foo;
+''';
+
+final reexportingLibraryUri = new Uri('reexporting.dart');
+const String REEXPORTING_LIBRARY_SOURCE = '''
+library reexporting;
+export 'exporting.dart';
+''';
+
+void main() {
+  var compiler = new MockCompiler();
+  compiler.registerSource(exportingLibraryUri, EXPORTING_LIBRARY_SOURCE);
+  compiler.registerSource(reexportingLibraryUri, REEXPORTING_LIBRARY_SOURCE);
+
+  // Load exporting library before the reexporting library.
+  var exportingLibrary = compiler.libraryLoader.loadLibrary(
+      exportingLibraryUri, null, exportingLibraryUri);
+  Expect.isTrue(exportingLibrary.exportsHandled);
+  var foo = findInExports(exportingLibrary, 'foo');
+  Expect.isNotNull(foo);
+  Expect.isTrue(foo.isField());
+
+  // Load reexporting library when exports are handled on the exporting library.
+  var reexportingLibrary = compiler.libraryLoader.loadLibrary(
+      reexportingLibraryUri, null, reexportingLibraryUri);
+  foo = findInExports(reexportingLibrary, 'foo');
+  Expect.isNotNull(foo);
+  Expect.isTrue(foo.isField());
+}
+
+Element findInExports(LibraryElement library, String name) {
+  for (var export in library.exports) {
+    if (export.name.slowToString() == name) {
+      return export;
+    }
+  }
+  return null;
+}