Teach ninja to handle output directories outside the source dir.

test/generator-output/gyptest-mac-bundle.py

 #!/usr/bin/env python
 
 # Copyright (c) 2012 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Verifies mac bundles work with --generator-output.
 """
 
 import TestGyp
 
 import sys
 
 if sys.platform == 'darwin':
-  # Ninja doesn't support --generator-output.
-  test = TestGyp.TestGyp(formats=['!ninja'])
+  test = TestGyp.TestGyp(formats=[])
 
   MAC_BUNDLE_DIR = 'mac-bundle'
   GYPFILES_DIR = 'gypfiles'
   test.writable(test.workpath(MAC_BUNDLE_DIR), False)
   test.run_gyp('test.gyp',
                '--generator-output=' + test.workpath(GYPFILES_DIR),
                chdir=MAC_BUNDLE_DIR)
   test.writable(test.workpath(MAC_BUNDLE_DIR), True)
 
   test.build('test.gyp', test.ALL, chdir=GYPFILES_DIR)
 
   test.pass_test()