Teach ninja to handle output directories outside the source dir.

test/subdirectory/gyptest-subdir-all.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 building a subsidiary dependent target from a .gyp file in a
 subdirectory, without specifying an explicit output build directory,
 and using the subdirectory's solution or project file as the entry point.
 """
 
 import TestGyp
 
-# Ninja and Android don't support running from subdirectories.
+# Android doesn't support running from subdirectories.
+# Ninja doesn't support relocation.
 test = TestGyp.TestGyp(formats=['!ninja', '!android'])
 
 test.run_gyp('prog1.gyp', chdir='src')
 
 test.relocate('src', 'relocate/src')
 
 chdir = 'relocate/src/subdir'
 target = test.ALL
 
 test.build('prog2.gyp', target, chdir=chdir)
 
 test.built_file_must_not_exist('prog1', type=test.EXECUTABLE, chdir=chdir)
 
 test.run_built_executable('prog2',
                           chdir=chdir,
                           stdout="Hello from prog2.c\n")
 
 test.pass_test()