Introduce the legium component in test.dart, and start support for dart:dom and dart:html.

frog/leg/native_handler.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('native');
 #import('leg.dart');
 #import('elements/elements.dart');
 #import('scanner/scannerlib.dart');
 #import('ssa/ssa.dart');
 #import('tree/tree.dart');
@@ skipping 12 matching lines @@
         // otherwise it will only be parsed if there is a call to
         // one of its constructor.
         element.parseNode(compiler);
         // Resolve to setup the inheritance.
         element.resolve(compiler);
       }
     }
   }
 }
 
-void checkNativeSupport(Compiler compiler, LibraryElement library) {
-  if (library.script.name.contains('dart/frog/tests/native/src')) {
+void checkNativeSupport(Compiler compiler,
+                        LibraryElement library,
+                        [libraryName = '']) {
+  if (library.script.name.contains('dart/frog/tests/native/src')
+      || libraryName == 'dart:dom'
+      || libraryName == 'dart:html') {
     library.define(new ForeignElement(
         const SourceString('native'), library), compiler);
   }
 }
 
 Token handleNativeBlockToSkip(Listener listener, Token token) {
  token = token.next;
   if (token.kind === STRING_TOKEN) {
     token = token.next;
   }
@@ skipping 164 matching lines @@
   } else if (!node.arguments.tail.isEmpty()) {
     builder.compiler.cancel('More than one argument to native');
   } else {
     LiteralString jsCode = node.arguments.head;
     int start = jsCode.value.slowToString()[0] === '@' ? 1 : 0;
     builder.push(new HForeign(builder.unquote(jsCode, start),
                               const SourceString('Object'),
                               <HInstruction>[]));
   }
 }