Incremental build is now off by default

tools/testing/dart/test_runner.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Classes and methods for executing tests.
  *
  * This module includes:
  * - Managing parallel execution of tests, including timeout checks.
  * - Evaluating the output of each test as pass/fail/crash/timeout.
@@ skipping 455 matching lines @@
         _process.close();
         _startProcess(() {
           _reportResult(">>> TEST TIMEOUT");
         });
       };
       _process.kill();
     };
   }
 
   void _startProcess(then) {
-    _process = new Process.start(_executable, ['-batch']);
+    _process = new Process.start(_executable, ['--batch']);
     _stdoutStream = new StringInputStream(_process.stdout);
     _stderrStream = new StringInputStream(_process.stderr);
     _testStdout = new List<String>();
     _testStderr = new List<String>();
     _stdoutStream.lineHandler = _readOutput(_stdoutStream, _testStdout);
     _stderrStream.lineHandler = _readOutput(_stderrStream, _testStderr);
     _process.exitHandler = _exitHandler;
     _process.startHandler = then;
   }
 }
@@ skipping 230 matching lines @@
         // the developer doesn't waste his or her time trying to fix a bunch of 
         // tests that appear to be broken but were actually just flakes that 
         // didn't get retried because there had already been one failure.
         new RunningProcess(test, 
             _MAX_FAILED_NO_RETRY > _progress.numFailedTests).start();
       }
       _numProcesses++;
     }
   }
 }