Update fetch to support more flexible refspecs

recipes/nacl.py

 # Copyright 2014 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.
 
 import sys
 
 import recipe_util  # pylint: disable=F0401
 
 
 # This class doesn't need an __init__ method, so we disable the warning
 # pylint: disable=W0232
 class NaCl(recipe_util.Recipe):
   """Basic Recipe class for NaCl."""
 
   @staticmethod
   def fetch_spec(props):
     url = ('https://chromium.googlesource.com/native_client/'
            'src/native_client.git')
-    solution = { 'name'   :'native_client',
-                 'url'    : url,
-                 'deps_file': '.DEPS.git',
-                 'managed'   : False,
-                 'custom_deps': {},
-                 'safesync_url': '',
+    solution = {
+        'name'        : 'native_client',
+        'url'         : url,
+        'deps_file'   : '.DEPS.git',
+        'managed'     : False,
+        'custom_deps' : {},
+        'safesync_url': '',
     }
     spec = {
       'solutions': [solution],
-      'svn_url': 'svn://svn.chromium.org/native_client',
-      'svn_branch': 'trunk/src/native_client',
-      'svn_ref': 'master',
+      'auto': True
     }
     if props.get('submodule_git_svn_spec'):
       spec['submodule_git_svn_spec'] = props['submodule_git_svn_spec']
     if props.get('target_os'):
       spec['target_os'] = props['target_os'].split(',')
     if props.get('target_os_only'):
       spec['target_os_only'] = props['target_os_only']
     checkout_type = 'gclient_git_svn'
     if props.get('nosvn'):
       checkout_type = 'gclient_git'
     spec_type = '%s_spec' % checkout_type
     return {
       'type': checkout_type,
       spec_type: spec,
     }
 
   @staticmethod
   def expected_root(_props):
     return 'native_client'
 
 
 def main(argv=None):
   return NaCl().handle_args(argv)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))