sync: Add pre-commit update avoidance mode + flag

sync/tools/testserver/sync_testserver.py

 #!/usr/bin/env python
 # 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.
 
 """This is a python sync server used for testing Chrome Sync.
 
 By default, it listens on an ephemeral port and xmpp_port and sends the port
 numbers back to the originating process over a pipe. The originating process can
 specify an explicit port and xmpp_port if necessary.
@@ skipping 132 matching lines @@
                     self.ChromiumSyncDisableNotificationsOpHandler,
                     self.ChromiumSyncEnableNotificationsOpHandler,
                     self.ChromiumSyncSendNotificationOpHandler,
                     self.ChromiumSyncBirthdayErrorOpHandler,
                     self.ChromiumSyncTransientErrorOpHandler,
                     self.ChromiumSyncErrorOpHandler,
                     self.ChromiumSyncSyncTabFaviconsOpHandler,
                     self.ChromiumSyncCreateSyncedBookmarksOpHandler,
                     self.ChromiumSyncEnableKeystoreEncryptionOpHandler,
                     self.ChromiumSyncRotateKeystoreKeysOpHandler,
-                    self.ChromiumSyncEnableManagedUserAcknowledgementHandler]
+                    self.ChromiumSyncEnableManagedUserAcknowledgementHandler,
+                    self.ChromiumSyncEnablePreCommitGetUpdateAvoidanceHandler]
 
     post_handlers = [self.ChromiumSyncCommandHandler,
                      self.ChromiumSyncTimeHandler]
     testserver_base.BasePageHandler.__init__(self, request, client_address,
                                              sync_http_server, [], get_handlers,
                                              [], post_handlers, [])
 
 
   def ChromiumSyncTimeHandler(self):
     """Handle Chromium sync .../time requests.
@@ skipping 256 matching lines @@
       return False
     result, raw_reply = (
         self.server._sync_handler.HandleEnableManagedUserAcknowledgement())
     self.send_response(result)
     self.send_header('Content-Type', 'text/html')
     self.send_header('Content-Length', len(raw_reply))
     self.end_headers()
     self.wfile.write(raw_reply)
     return True
 
+  def ChromiumSyncEnablePreCommitGetUpdateAvoidanceHandler(self):
+    test_name = "/chromiumsync/enableprecommitgetupdateavoidance"
+    if not self._ShouldHandleRequest(test_name):
+      return False
+    result, raw_reply = (
+        self.server._sync_handler.HandleEnablePreCommitGetUpdateAvoidance())
+    self.send_response(result)
+    self.send_header('Content-Type', 'text/html')
+    self.send_header('Content-Length', len(raw_reply))
+    self.end_headers()
+    self.wfile.write(raw_reply)
+    return True
+
 class SyncServerRunner(testserver_base.TestServerRunner):
   """TestServerRunner for the net test servers."""
 
   def __init__(self):
     super(SyncServerRunner, self).__init__()
 
   def create_server(self, server_data):
     port = self.options.port
     host = self.options.host
     xmpp_port = self.options.xmpp_port
@@ skipping 11 matching lines @@
     testserver_base.TestServerRunner.add_options(self)
     self.option_parser.add_option('--xmpp-port', default='0', type='int',
                                   help='Port used by the XMPP server. If '
                                   'unspecified, the XMPP server will listen on '
                                   'an ephemeral port.')
     # Override the default logfile name used in testserver.py.
     self.option_parser.set_defaults(log_file='sync_testserver.log')
 
 if __name__ == '__main__':
   sys.exit(SyncServerRunner().main())