Fix error printing in gcl.GetRepositoryRoot() and fix its unit tests.

gcl.py

 #!/usr/bin/python
 # Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # Wrapper script around Rietveld's upload.py that groups files into
 # changelists.
 
 import getpass
 import os
@@ skipping 83 matching lines @@
   global repository_root
   if not repository_root:
     infos = gclient.CaptureSVNInfo(os.getcwd(), print_error=False)
     cur_dir_repo_root = infos.get("Repository Root")
     if not cur_dir_repo_root:
       raise Exception("gcl run outside of repository")
 
     repository_root = os.getcwd()
     while True:
       parent = os.path.dirname(repository_root)
-      if (gclient.CaptureSVNInfo(parent).get("Repository Root") !=
-          cur_dir_repo_root):
+      if (gclient.CaptureSVNInfo(parent, print_error=False).get(
+              "Repository Root") != cur_dir_repo_root):
         break
       repository_root = parent
   return repository_root
 
 
 def GetInfoDir():
   """Returns the directory where gcl info files are stored."""
   global gcl_info_dir
   if not gcl_info_dir:
     gcl_info_dir = os.path.join(GetRepositoryRoot(), '.svn', 'gcl_info')
@@ skipping 981 matching lines @@
     # the files. This allows commands such as 'gcl diff xxx' to work.
     args =["svn", command]
     root = GetRepositoryRoot()
     args.extend([os.path.join(root, x) for x in change_info.FileList()])
     RunShell(args, True)
   return 0
 
 
 if __name__ == "__main__":
   sys.exit(main())