Add NativeEnqueuer to work with the Enqueuer.

sdk/lib/_internal/compiler/implementation/dart2js.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.
 
 library dart2js;
 
 import 'dart:io';
 import 'dart:uri';
 import 'dart:utf';
 
@@ skipping 146 matching lines @@
                       (_) => enableColors = false),
     new OptionHandler('--enable-diagnostic-colors', (_) => enableColors = true),
     new OptionHandler('--enable[_-]checked[_-]mode|--checked',
                       (_) => passThrough('--enable-checked-mode')),
     new OptionHandler('--enable-concrete-type-inference',
                       (_) => passThrough('--enable-concrete-type-inference')),
     new OptionHandler(r'--help|/\?|/h', (_) => wantHelp = true),
     new OptionHandler('--package-root=.+|-p.+', setPackageRoot),
     new OptionHandler('--disallow-unsafe-eval', passThrough),
     new OptionHandler('--analyze-all', passThrough),
+    new OptionHandler('--enable-native-live-type-analysis', passThrough),
     // The following two options must come last.
     new OptionHandler('-.*', (String argument) {
       helpAndFail('Error: Unknown option "$argument".');
     }),
     new OptionHandler('.*', (String argument) {
       arguments.add(nativeToUriPath(argument));
     })
   ];
 
   parseCommandLine(handlers, argv);
@@ skipping 225 matching lines @@
   --library-root=<directory>
     Where to find the Dart platform libraries.
 
   --allow-mock-compilation
     Do not generate a call to main if either of the following
     libraries are used: dart:dom, dart:html dart:io.
 
   --enable-concrete-type-inference
     Enable experimental concrete type inference.
 
+  --enable-native-live-type-analysis
+    Remove unused native types from dart:html and related libraries. This is
+    expected to become the default behavior.
+
   --disallow-unsafe-eval
     Disables dynamic generation of code in the generated output. This is
     necessary to satisfy CSP restrictions (see http://www.w3.org/TR/CSP/).
     This flag is not continuously tested. Please report breakages and we
     will fix them as soon as possible.''');
 }
 
 void helpAndExit(bool verbose) {
   if (verbose) {
     verboseHelp();
@@ skipping 18 matching lines @@
     } catch (ignored) {
       print('Internal error: error while printing exception');
     }
     try {
       print(trace);
     } finally {
       exit(253); // 253 is recognized as a crash by our test scripts.
     }
   }
 }