Unify the name of the flag and make it settable from command line.

tests/compiler/dart2js/unparser_test.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.
 
 #import('dart:uri');
 #import('parser_helper.dart');
 #import('mock_compiler.dart');
 #import("../../../lib/compiler/compiler.dart");
 #import("../../../lib/compiler/implementation/leg.dart", prefix:'leg');
 #import("../../../lib/compiler/implementation/dart_backend/dart_backend.dart");
@@ skipping 69 matching lines @@
   }
 
   handler(uri, begin, end, message, kind) {
     if (kind === Diagnostic.ERROR || kind === Diagnostic.CRASH) {
       Expect.fail('$uri: $begin-$end: $message [$kind]');
     }
   }
 
   final options = <String>['--output-type=dart'];
   if (minify) options.add('--minify');
-  if (cutDeclarationTypes) options.add('--cutDeclarationTypes');
+  if (cutDeclarationTypes) options.add('--cut-declaration-types');
 
   compile(
       scriptUri,
       fileUri('libraryRoot'),
       fileUri('packageRoot'),
       provider,
       handler,
       options).then(continuation);
 }
 
@@ skipping 741 matching lines @@
   testDoubleMains();
   testInterfaceDefaultAnotherLib();
   testStaticAccessIoLib();
   testLocalFunctionPlaceholder();
   testMinification();
   testClosureLocalsMinified();
   testParametersMinified();
   testTypeVariablesInDifferentLibraries();
   testDeclarationTypePlaceholders();
 }