dart:html perf optimization based on runing Dromaeo benchmarks

samples/third_party/dromaeo/Suites.dart

 #library('Suites.dart');
 
 class Origin {
   final String author;
   final String url;
 
   const Origin(this.author, this.url);
 }
 
 class SuiteDescription {
   final String file;
   final String name;
   final Origin origin;
   final String description;
   final List<String> tags;
 
   const SuiteDescription(this.file, this.name, this.origin,
                          this.description, this.tags);
 }
 
 class Suites {
   static final JOHN_RESIG = const Origin('John Resig', 'http://ejohn.org/');
 
   static final CATEGORIES = const {
     'dom': 'DOM Core Tests (dart:dom)',
     'html': 'DOM Core Tests (dart:html)',
+    'htmlfast': 'DOM Core Tests (dart:html) Fast',
     'js': 'DOM Core Tests (JavaScript)',
     'dart': 'DOM Core Tests (dart)',
     'frog': 'DOM Core Tests (frog)',
   };
 
   static final _CORE_SUITE_DESCRIPTIONS = const [
       const SuiteDescription(
           'dom-attr.html',
           'DOM Attributes',
           JOHN_RESIG,
@@ skipping 31 matching lines @@
           suite.description,
           combined);
     }
     return suites.map(getVariant);
   }
 
   // Mappings from original path to Dart-specific variants.
   static _jsPath(path) => path;
   static _domPath(path) => path.replaceFirst('.html', '-dom.html');
   static _htmlPath(path) => path.replaceFirst('.html', '-html.html');
+  static _htmlFastPath(path) => path.replaceFirst('.html', '-htmlfast.html');
   static _frogDomPath(path) =>
       'frog/${path.replaceFirst(".html", "-dom-js.html")}';
   static _frogHtmlPath(path) =>
       'frog/${path.replaceFirst(".html", "-html-js.html")}';
+  static _frogHtmlFastPath(path) =>
+      'frog/${path.replaceFirst(".html", "-htmlfast-js.html")}';
 
   static var _SUITE_DESCRIPTIONS;
 
   static List<SuiteDescription> get SUITE_DESCRIPTIONS() {
     if (null !== _SUITE_DESCRIPTIONS) {
       return _SUITE_DESCRIPTIONS;
     }
     _SUITE_DESCRIPTIONS = <SuiteDescription>[];
     add(variant, mapper, tags) {
       _SUITE_DESCRIPTIONS.addAll(
           getVariants(_CORE_SUITE_DESCRIPTIONS, variant, mapper, tags));
     }
     add('js', _jsPath, ['js']);
     add('dart:dom', _domPath, ['dart', 'dom']);
     add('dart:html', _htmlPath, ['dart', 'html']);
+    add('dart:html fast', _htmlPath, ['dart', 'htmlfast']);
     add('frog dart:dom', _frogDomPath, ['frog', 'dom']);
     add('frog dart:html', _frogHtmlPath, ['frog', 'html']);
+    add('frog dart:html fast', _frogHtmlFastPath, ['frog', 'htmlfast']);
     return _SUITE_DESCRIPTIONS;
   }
 
   static List<SuiteDescription> getSuites(String tags) {
     // A disjunction of conjunctions (e.g.,
     // 'js&modify|dart&dom&modify').
     final taglist = tags.split('|').map((tag) => tag.split('&'));
 
     bool match(suite) {
       // If any conjunction matches, return true.
@@ skipping 15 matching lines @@
       return CATEGORIES[tags];
     }
     for (final suite in _CORE_SUITE_DESCRIPTIONS) {
       if (suite.tags[0] == tags) {
         return suite.name;
       }
     }
     return null;
   }
 }