Docserver: Use GitilesFileSystem instead of SubversionFileSystem

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

Index: chrome/common/extensions/docs/server2/file_system.py
diff --git a/chrome/common/extensions/docs/server2/file_system.py b/chrome/common/extensions/docs/server2/file_system.py
index 7a5ac4fdbd45bdcc605ef373b4a3ddef9d9cd928..9eaabdf16b1492bf0f4bcffbb0773436a7268170 100644
--- a/chrome/common/extensions/docs/server2/file_system.py
+++ b/chrome/common/extensions/docs/server2/file_system.py
@@ -29,6 +29,14 @@ class FileNotFoundError(_BaseFileSystemException):
     _BaseFileSystemException.__init__(self, filename)
 
 
+class FileSystemThrottledError(_BaseFileSystemException):
+  '''Raised when access to a file system resource is temporarily unavailable
+  due to service throttling.
+  '''
+  def __init__(self, filename):
+    _BaseFileSystemException.__init__(self, filename)
+
+
 class FileSystemError(_BaseFileSystemException):
   '''Raised on when there are errors reading or statting files, such as a
   network timeout.