Add NativeEnqueuer to work with the Enqueuer.

sdk/lib/_internal/compiler/implementation/dart2js.dart

Index: sdk/lib/_internal/compiler/implementation/dart2js.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart2js.dart b/sdk/lib/_internal/compiler/implementation/dart2js.dart
index 55a016e10ea5ef35b8dfe5fa670a2d4b181b5ff0..474cdad82e98686f9aab2e68ffbfadea6deb3d36 100644
--- a/sdk/lib/_internal/compiler/implementation/dart2js.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart2js.dart
@@ -164,6 +164,7 @@ void compile(List<String> argv) {
     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".');
@@ -409,6 +410,10 @@ be removed in a future version:
   --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/).