Switch from {...} to dict((...)) generator syntax. The former doesn't work in

chrome/common/extensions/docs/server2/patched_file_system.py

 # Copyright 2013 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.
 
 from copy import deepcopy
 
 from file_system import FileSystem, StatInfo, FileNotFoundError
 from future import Future
 
 class _AsyncFetchFuture(object):
   def __init__(self,
                unpatched_files_future,
                patched_files_future,
                dirs_value,
                patched_file_system):
     self._unpatched_files_future = unpatched_files_future
     self._patched_files_future = patched_files_future
     self._dirs_value  = dirs_value
     self._patched_file_system = patched_file_system
 
   def Get(self):
     files = self._unpatched_files_future.Get()
     files.update(self._patched_files_future.Get())
-    files.update({path: self._PatchDirectoryListing(path,
-                                                    self._dirs_value[path])
-                  for path in self._dirs_value})
+    files.update(
+        dict((path, self._PatchDirectoryListing(path, self._dirs_value[path]))
+             for path in self._dirs_value))
     return files
 
   def _PatchDirectoryListing(self, path, original_listing):
     added, deleted, modified = (
         self._patched_file_system._GetDirectoryListingFromPatch(path))
     if original_listing is None:
       if len(added) == 0:
         raise FileNotFoundError('Directory %s not found in the patch.' % path)
       return added
     return list((set(original_listing) | set(added)) - set(deleted))
@@ skipping 111 matching lines @@
       # No changes are made in this directory.
       return self._host_file_system.Stat(path)
 
     if stat_info.child_versions is not None:
       if filename:
         if filename in stat_info.child_versions:
           stat_info = StatInfo(stat_info.child_versions[filename])
         else:
           raise FileNotFoundError('%s was not in child versions' % filename)
     return stat_info