enable batch mode for dartdevc tests, also fix status so ddc bots pass

tools/testing/dart/configuration.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'compiler_configuration.dart';
 import 'http_server.dart';
@@ skipping 338 matching lines @@
       print("-rflutter requires the flutter engine executable to "
           "be specified using --flutter");
       isValid = false;
     }
 
     if (runtime == Runtime.flutter && architecture != Architecture.x64) {
       isValid = false;
       print("-rflutter is applicable only for --arch=x64");
     }
 
-    if (compiler == Compiler.dartdevc && !useSdk) {
-      isValid = false;
-      print("--compiler dartdevc requires --use-sdk");
-    }
-
     if (compiler == Compiler.dartdevc && !isStrong) {
       isValid = false;
       print("--compiler dartdevc requires --strong");
     }
 
     return isValid;
   }
 
   /// Starts global HTTP servers that serve the entire dart repo.
   ///
@@ skipping 363 matching lines @@
 
       case macos:
         return 'xcodebuild/';
     }
 
     throw "unreachable";
   }
 
   String toString() => "System($name)";
 }