Make List.from and Iterable.toList default to not growable.

samples/third_party/dromaeo/Suites.dart

 library Suites;
 
 class Origin {
   final String author;
   final String url;
 
   const Origin(this.author, this.url);
 }
 
 class SuiteDescription {
@@ skipping 95 matching lines @@
     // Expand the list to include a unique SuiteDescription for each
     // tested variant.
     for (SuiteDescription suite in _CORE_SUITE_DESCRIPTIONS) {
       List variants = suite.testVariants;
       for (List variant in variants) {
         assert(variant.length == 2);
         String platform = variant[0];
         List<String> libraries = variant[1];
         for(String lib in libraries) {
           String path = _getHtmlPathForVariant(platform, lib, suite.file);
-          final combined = new List.from(suite.tags, growable: true);
+          final combined = new List.from(suite.tags);
           combined.add(platform);
           if (lib != '') {
             combined.add(lib);
             lib = ':$lib';
           }
           final name = (variant == null)
               ? suite.name
               : '${suite.name} ($platform$lib)';
           _SUITE_DESCRIPTIONS.add(new SuiteDescription(
                                       path,
@@ skipping 37 matching lines @@
       return CATEGORIES[tags];
     }
     for (final suite in _CORE_SUITE_DESCRIPTIONS) {
       if (suite.tags[0] == tags) {
         return suite.name;
       }
     }
     return null;
   }
 }