Add a cheap trick to disable parallel sync on the buildbot until they are fixed.

This way engineers can still enjoy the perf benefit while someone fixes the
buildbot stdio parsing issue.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/3334017

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@59127 0039d316-1c4b-4281-b951-d872f2087c98

gclient.py

@@ -1175,7 +1175,14 @@ def Main(argv):
         '  %-10s %s' % (fn[3:], Command(fn[3:]).__doc__.split('\n')[0].strip())
         for fn in dir(sys.modules[__name__]) if fn.startswith('CMD')]))
     parser = optparse.OptionParser(version='%prog ' + __version__)
-    parser.add_option('-j', '--jobs', default=1, type='int',
+    # TODO(maruel): Temporary workaround to disable parallel checkout on
+    # buildbots until they can correctly parse its output. Uses that fact that
+    # stdout is redirected as a signal.
+    if sys.stdout.isatty():
+      jobs = 8
+    else:
+      jobs = 1
+    parser.add_option('-j', '--jobs', default=jobs, type='int',
                       help='Specify how many SCM commands can run in parallel; '
                            'default=%default')
     parser.add_option('-v', '--verbose', action='count', default=0,