Add support for compiling Dart via the FE in dart2js.

pkg/compiler/lib/src/deferred_load.dart

 // Copyright (c) 2014, 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 deferred_load;
 
 import 'common/tasks.dart' show CompilerTask;
 import 'common.dart';
 import 'compiler.dart' show Compiler;
 import 'constants/expressions.dart' show ConstantExpression;
@@ skipping 796 matching lines @@
               _assignNamesToOutputUnits(allOutputUnits);
             }));
     // Notify the impact strategy impacts are no longer needed for deferred
     // load.
     compiler.impactStrategy.onImpactUsed(IMPACT_USE);
   }
 
   void beforeResolution(LibraryEntity mainLibrary) {
     if (mainLibrary == null) return;
     // TODO(johnniwinther): Support deferred load for kernel based elements.
-    if (compiler.options.loadFromDill) return;
+    if (compiler.options.useKernel) return;
     _allDeferredImports[_fakeMainImport] = mainLibrary;
     var lastDeferred;
     // When detecting duplicate prefixes of deferred libraries there are 4
     // cases of duplicate prefixes:
     // 1.
     // import "lib.dart" deferred as a;
     // import "lib2.dart" deferred as a;
     // 2.
     // import "lib.dart" deferred as a;
     // import "lib2.dart" as a;
@@ skipping 294 matching lines @@
 
   bool operator ==(other) {
     if (other is! _DeclaredDeferredImport) return false;
     return declaration == other.declaration;
   }
 
   int get hashCode => declaration.hashCode * 17;
 
   String toString() => '$declaration';
 }