Update defer loading algorithm:

pkg/compiler/lib/src/dump_info.dart

Index: pkg/compiler/lib/src/dump_info.dart
diff --git a/pkg/compiler/lib/src/dump_info.dart b/pkg/compiler/lib/src/dump_info.dart
index cc292e4c55b0af777267c083f3248985a609e0ed..21900936043db14911b85c616c4239a7f1a6e210 100644
--- a/pkg/compiler/lib/src/dump_info.dart
+++ b/pkg/compiler/lib/src/dump_info.dart
@@ -348,8 +348,7 @@ class ElementInfoCollector extends BaseElementVisitor<Info, dynamic> {
       assert(outputUnit.name != null || outputUnit.isMainOutput);
       OutputUnitInfo info = new OutputUnitInfo(
           outputUnit.name, backend.emitter.emitter.generatedSize(outputUnit));
-      info.imports.addAll(outputUnit.imports
-          .map((d) => compiler.deferredLoadTask.importDeferName[d]));
+      info.imports.addAll(compiler.deferredLoadTask.getImportNames(outputUnit));
       result.outputUnits.add(info);
       return info;
     });