Docserver: achieve online vs offline (cron vs instance) behaviour at the object

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

Index: chrome/common/extensions/docs/server2/local_file_system.py
diff --git a/chrome/common/extensions/docs/server2/local_file_system.py b/chrome/common/extensions/docs/server2/local_file_system.py
index 2955d8c64b35149635862a059850a49270213674..d243583638a27f7eab8cb05466e9986f6f94123a 100644
--- a/chrome/common/extensions/docs/server2/local_file_system.py
+++ b/chrome/common/extensions/docs/server2/local_file_system.py
@@ -3,15 +3,19 @@
 # found in the LICENSE file.
 
 import os
+import sys
 
 from file_system import FileSystem, FileNotFoundError, StatInfo, ToUnicode
 from future import Future
 
 class LocalFileSystem(FileSystem):
-  """FileSystem implementation which fetches resources from the local
+  '''FileSystem implementation which fetches resources from the local
   filesystem.
-  """
-  def __init__(self, base_path):
+  '''
+  def __init__(self, base_path=None):
+    if base_path is None:
+      # Default to the base of the extensions directory.
+      base_path = os.path.join(sys.path[0], os.pardir, os.pardir)
     self._base_path = self._ConvertToFilepath(base_path)
 
   def _ConvertToFilepath(self, path):