Replace dart_core.js with actual compiled SDK

lib/src/dependency_graph.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.
 
 /// Tracks the shape of the import/export graph and dependencies between files.
 library dev_compiler.src.dependency_graph;
 
 import 'dart:collection' show HashSet;
 
 import 'package:analyzer/analyzer.dart' show parseDirectives;
@@ skipping 447 matching lines @@
 class DependencyGraphError extends MessageWithSpan {
   const DependencyGraphError(String message, SourceSpan span)
       : super(message, Level.SEVERE, span);
 }
 
 /// Runtime files added to all applications when running the compiler in the
 /// command line.
 const defaultRuntimeFiles = const [
   'harmony_feature_check.js',
   'dart_runtime.js',
-  'dart_core.js'
+  'dart/core.js',
+  'dart/math.js'
 ];
 
 /// Runtime files added to applications when running in server mode.
 final runtimeFilesForServerMode = new List<String>.from(defaultRuntimeFiles)
   ..addAll(const ['messages_widget.js', 'messages.css']);
 
 final _log = new Logger('dev_compiler.dependency_graph');