Python 3 compatibility

test/symlinks/gyptest-symlinks.py

 #!/usr/bin/env python
 
 # Copyright (c) 2015 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.
 
 """
 Test that RelativePath(s, d) doesn't return a path starting with '..' when
 s is textually below d, but is also a symlink to a file that is not below d.
 
@@ skipping 10 matching lines @@
 import sys
 import tempfile
 
 if sys.platform != 'win32':
   test = TestGyp.TestGyp()
 
   # Copy hello.gyp and hello.c to temporary named files, which will then be
   # symlinked back and processed. Note that we don't ask gyp to touch the
   # original files at all; they are only there as source material for the copy.
   # That's why hello.gyp references symlink_hello.c instead of hello.c.
-  with tempfile.NamedTemporaryFile() as gyp_file:
-    with tempfile.NamedTemporaryFile() as c_file:
+  with tempfile.NamedTemporaryFile(mode='w+') as gyp_file:
+    with tempfile.NamedTemporaryFile(mode='w+') as c_file:
       with open('hello.gyp') as orig_gyp_file:
         gyp_file.write(orig_gyp_file.read())
         gyp_file.flush()
       with open('hello.c') as orig_c_file:
         c_file.write(orig_c_file.read())
         c_file.flush()
       # We need to flush the files because we want to read them before closing
       # them, since when they are closed they will be deleted.
 
       # Don't proceed with the test on a system that doesn't let you read from
@@ skipping 14 matching lines @@
       os.symlink(gyp_file.name, symlink_gyp)
       os.symlink(c_file.name, symlink_c)
 
       # Run gyp on the symlinked files.
       test.run_gyp(symlink_gyp, chdir=outdir)
       test.build(symlink_gyp, chdir=outdir)
       test.run_built_executable('symlink_hello', stdout="Hello, world!\n",
                                 chdir=outdir)
 
       test.pass_test()