Only pass an AssetId to isPrimary and declareOutputs.

pkg/polymer/lib/src/build/import_inliner.dart

 // Copyright (c) 2013, 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.
 
 /// Transfomer that inlines polymer-element definitions from html imports.
 library polymer.src.build.import_inliner;
 
 import 'dart:async';
 import 'dart:convert';
 
@@ skipping 233 matching lines @@
 ///
 /// This transformer assumes that all script tags point to external files. To
 /// support script tags with inlined code, use this transformer after running
 /// [InlineCodeExtractor] on an earlier phase.
 class ImportInliner extends Transformer {
   final TransformOptions options;
 
   ImportInliner(this.options);
 
   /// Only run on entry point .html files.
-  Future<bool> isPrimary(Asset input) =>
-      new Future.value(options.isHtmlEntryPoint(input.id));
+  Future<bool> isPrimary(AssetId id) =>
+      new Future.value(options.isHtmlEntryPoint(id));
 
   Future apply(Transform transform) =>
       new _HtmlInliner(options, transform).apply();
 }
 
 const TYPE_DART = 'application/dart';
 const TYPE_JS = 'text/javascript';
 
 /// Internally adjusts urls in the html that we are about to inline.
 class _UrlNormalizer extends TreeVisitor {
@@ skipping 118 matching lines @@
   'formaction', // in button, input
   'href',       // in a, area, link, base, command
   'icon',       // in command
   'manifest',   // in html
   'poster',     // in video
   'src',        // in audio, embed, iframe, img, input, script, source, track,
                 //    video
 ];
 
 _getSpan(SourceFile file, AstNode node) => file.span(node.offset, node.end);