Add NativeEnqueuer to work with the Enqueuer.

sdk/lib/_internal/compiler/implementation/js_backend/backend.dart

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 typedef void Recompile(Element element);
 
 class ReturnInfo {
   HType returnType;
@@ skipping 798 matching lines @@
       compiler.codegenWorld.addBailoutCode(work, codeBuffer);
       optimizer.prepareForSpeculativeOptimizations(work, graph);
       optimizer.optimize(work, graph, true);
     }
     CodeBuffer codeBuffer = generator.generateCode(work, graph);
     compiler.codegenWorld.addGeneratedCode(work, codeBuffer);
     invalidateAfterCodegen.forEach(compiler.enqueuer.codegen.eagerRecompile);
     invalidateAfterCodegen.clear();
   }
 
-  void processNativeClasses(Enqueuer world,
-                            Collection<LibraryElement> libraries) {
-    native.processNativeClasses(world, emitter, libraries);
+
+  native.NativeEnqueuer nativeResolutionEnqueuer(Enqueuer world) {
+    return new native.NativeResolutionEnqueuer(world, compiler);
+  }
+
+  native.NativeEnqueuer nativeCodegenEnqueuer(Enqueuer world) {
+    return new native.NativeCodegenEnqueuer(world, compiler, emitter);
   }
 
   void assembleProgram() {
     emitter.assembleProgram();
   }
 
   /**
    * Documentation wanted -- johnniwinther
    *
    * Invariant: [element] must be a declaration element.
@@ skipping 188 matching lines @@
     print("Inferred return types:");
     print("----------------------");
     dumpReturnTypes();
     print("");
     print("Inferred field types:");
     print("------------------------");
     fieldTypes.dump();
     print("");
   }
 }