[Sync] Allow sync start without sign-in if the local sync backend is on.

components/sync/test/engine/mock_connection_manager.h

 // Copyright (c) 2012 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.
 
 #ifndef COMPONENTS_SYNC_TEST_ENGINE_MOCK_CONNECTION_MANAGER_H_
 #define COMPONENTS_SYNC_TEST_ENGINE_MOCK_CONNECTION_MANAGER_H_
 
 #include <stdint.h>
 
 #include <bitset>
@@ skipping 250 matching lines @@
 
   // Explicitly indicate that we will not be fetching some updates.
   void ClearUpdatesQueue() { update_queue_.clear(); }
 
   // Locate the most recent update message for purpose of alteration.
   sync_pb::SyncEntity* GetMutableLastUpdate();
 
   // Adds a new progress marker to the last update.
   sync_pb::DataTypeProgressMarker* AddUpdateProgressMarker();
 
+  void ResetAuthToken() { auth_token_.clear(); }
+
  private:
   sync_pb::SyncEntity* AddUpdateFull(syncable::Id id,
                                      syncable::Id parentid,
                                      const std::string& name,
                                      int64_t version,
                                      int64_t sync_ts,
                                      bool is_dir);
   sync_pb::SyncEntity* AddUpdateFull(const std::string& id,
                                      const std::string& parentid,
                                      const std::string& name,
@@ skipping 128 matching lines @@
   std::string next_token_;
 
   std::vector<sync_pb::ClientToServerMessage> requests_;
 
   DISALLOW_COPY_AND_ASSIGN(MockConnectionManager);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_TEST_ENGINE_MOCK_CONNECTION_MANAGER_H_