[polymer] fix editor hints -- query/queryAll and unused imports

pkg/polymer/lib/src/build/script_compactor.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 combines multiple dart script tags into a single one. */
 library polymer.src.build.script_compactor;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/src/generated/scanner.dart';
 import 'package:barback/barback.dart';
-import 'package:html5lib/parser.dart' show parseFragment;
 import 'package:path/path.dart' as path;
 import 'package:source_maps/span.dart' show SourceFile;
 
 import 'code_extractor.dart'; // import just for documentation.
 import 'common.dart';
 
 /**
  * Combines Dart script tags into a single script tag, and creates a new Dart
  * file that calls the main function of each of the original script tags.
  *
@@ skipping 19 matching lines @@
     var secondaryId = id.addExtension('.scriptUrls');
     var logger = transform.logger;
     return readPrimaryAsHtml(transform).then((document) {
       return transform.readInputAsString(secondaryId).then((libraryIds) {
         var libraries = (JSON.decode(libraryIds) as Iterable).map(
           (data) => new AssetId.deserialize(data)).toList();
         var mainLibraryId;
         var mainScriptTag;
         bool changed = false;
 
-        for (var tag in document.queryAll('script')) {
+        for (var tag in document.querySelectorAll('script')) {
           var src = tag.attributes['src'];
           if (src == 'packages/polymer/boot.js') {
             tag.remove();
             continue;
           }
           if (tag.attributes['type'] != 'application/dart') continue;
           if (src == null) {
             logger.warning('unexpected script without a src url. The '
               'ScriptCompactor transformer should run after running the '
               'InlineCodeExtractor', span: tag.sourceSpan);
@@ skipping 210 matching lines @@
       "() => Polymer.register('$tagName', $prefix.$typeName)";
 }
 
 _getSpan(SourceFile file, ASTNode node) => file.span(node.offset, node.end);
 
 const MAIN_HEADER = """
 library app_bootstrap;
 
 import 'package:polymer/polymer.dart';
 """;