anchor.diff:    "analyzer-checked-strong": [analyzer, noRuntime, checked, strong, useSdk],
     "analyzer-strong": [analyzer, noRuntime, strong, useSdk],
     "dart2js": [dart2js, chrome, useSdk, dart2jsBatch],
  -  "dart2js-d8-checked": [dart2js, d8, checked, fastStartup, useSdk, dart2jsBatch],
  +  "dart2js-d8-checked": [
  +    dart2js,
  +    d8,
  +    checked,
  +    fastStartup,
  +    useSdk,
  +    dart2jsBatch
  +  ],
     "dart2js-jsshell": [dart2js, jsshell, fastStartup, useSdk, dart2jsBatch],
     // TODO(rnystrom): Is it worth running dart2js on Firefox too?
     "dartdevc": [dartdevc, chrome, useSdk, strong],
   };
  +
  +/// A subset of the configurations that run quickly and give a decent amount of
  +/// coverage for the platforms that do not implement Dart 2.0 yet.
  +final oneConfigs = const [
  +  "vm",
  +  "vm-checked",
  +  "analyzer",
  +  "analyzer-checked",
  +  "dart2js",
  +  "dart2js-d8-checked",
  +  "dartdevc",
  +];
  +
  +/// The configurations that should correctly implement Dart 2.0 (more or less)
  +/// already.
  +final twoConfigs = const [
  +  "analyzer-checked-strong",
  +  "analyzer-strong",
  +  "dartdevc"
  +];
   
   final buildSteps = [
     // The SDK, which also builds the VM.
  
positive.code:     return;
    }
  
    var remainingArgs = []..addAll(argResults.rest);
  
    if (remainingArgs.length == 1) {
      remainingArgs.add(remainingArgs.first);
    }
  
    if (remainingArgs.length != 2) {
      usage(argParser);
      exit(1);
    }
  
    var build = argResults["build"] as bool;
    var configs = argResults["config"] as List<String>;
    if (configs.isEmpty) configs = allConfigs.keys.toList();
  
    var tests = scanTests();
  
    var startIndex = findFork(tests, remainingArgs[0]);
    var endIndex = findFork(tests, remainingArgs[1]);
  
    if (startIndex == null || endIndex == null) exit(1);
  
  
negative.code: }
  
  void usage(ArgParser parser) {
    print("Usage: dart run_tests.dart [--build] [-2] [-1] [--configs=...]"
        "<first file> [last file]");
    print("\n");
    print("Example:");
  