Compute WorldImpact in NativeEnqueuer.

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index c2f91fee4123a802c082b4713603f0b074dadf7c..b88c46294cba7424e8d9d250102ec5fcd481d85a 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -850,10 +850,10 @@ abstract class Compiler implements LibraryLoaderListener {
 
   void processQueue(Enqueuer enqueuer, Element main) {
     selfTask.measureSubtask("Compiler.processQueue", () {
-      WorldImpactBuilderImpl nativeImpact = new WorldImpactBuilderImpl();
-      enqueuer.nativeEnqueuer
-          .processNativeClasses(nativeImpact, libraryLoader.libraries);
-      enqueuer.applyImpact(impactStrategy, nativeImpact);
+      enqueuer.applyImpact(
+          impactStrategy,
+          enqueuer.nativeEnqueuer
+              .processNativeClasses(libraryLoader.libraries));
       if (main != null && !main.isMalformed) {
         FunctionElement mainMethod = main;
         mainMethod.computeType(resolution);