Load builtin helper libraries on demand.

tests/compiler/dart2js/memory_compiler.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 dart2js.test.memory_compiler;
 
 import 'package:expect/expect.dart';
 import 'memory_source_file_helper.dart';
 
 import '../../../sdk/lib/_internal/compiler/implementation/dart2jslib.dart'
@@ skipping 31 matching lines @@
                                    diagnosticHandler,
                                    libraryRoot,
                                    packageRoot,
                                    options);
   if (cachedCompiler != null) {
     compiler.coreLibrary = cachedCompiler.libraries['dart:core'];
     compiler.types = cachedCompiler.types;
     cachedCompiler.libraries.forEach((String uri, library) {
       if (library.isPlatformLibrary) {
         compiler.libraries[uri] = library;
-        compiler.onLibraryScanned(library, library.canonicalUri);
+        compiler.onLibraryLoaded(library, library.canonicalUri);
       }
     });
 
     compiler.symbolConstructor = cachedCompiler.symbolConstructor;
     compiler.mirrorSystemClass = cachedCompiler.mirrorSystemClass;
     compiler.mirrorsUsedClass = cachedCompiler.mirrorsUsedClass;
     compiler.mirrorSystemGetNameFunction =
         cachedCompiler.mirrorSystemGetNameFunction;
     compiler.symbolImplementationClass =
         cachedCompiler.symbolImplementationClass;
@@ skipping 28 matching lines @@
   }
 
   List<Uri> libraries = <Uri>[];
   memorySourceFiles.forEach((String path, _) {
     libraries.add(new Uri(scheme: 'memory', path: path));
   });
 
   return analyze(libraries, libraryRoot, packageRoot,
                  provider, diagnosticHandler, options);
 }