Teach ninja to handle output directories outside the source dir.

test/generator-output/gyptest-copies.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 file copies with --generator-output using an explicit build
 target of 'all'.
 """
 
 import TestGyp
 
-# Ninja and Android don't support --generator-output.
+# Android doesn't support --generator-output.
+# Ninja doesn't support relocation.
 test = TestGyp.TestGyp(formats=['!ninja', '!android'])
 
 test.writable(test.workpath('copies'), False)
 
 test.run_gyp('copies.gyp',
              '--generator-output=' + test.workpath('gypfiles'),
              chdir='copies')
 
 test.writable(test.workpath('copies'), True)
 
@@ skipping 25 matching lines @@
 
 if test.format == 'xcode':
   chdir = 'relocate/copies/subdir/build'
 elif test.format == 'make':
   chdir = 'relocate/gypfiles/out'
 else:
   chdir = 'relocate/gypfiles'
 test.must_match([chdir, 'Default', 'copies-out', 'file4'], "file4 contents\n")
 
 test.pass_test()