make new syncer thread the default.

chrome/browser/sync/js_sync_manager_observer.h

 // Copyright (c) 2011 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 CHROME_BROWSER_SYNC_JS_SYNC_MANAGER_OBSERVER_H_
 #define CHROME_BROWSER_SYNC_JS_SYNC_MANAGER_OBSERVER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 22 matching lines @@
   virtual void OnSyncCycleCompleted(
       const sessions::SyncSessionSnapshot* snapshot);
   virtual void OnAuthError(const GoogleServiceAuthError& auth_error);
   virtual void OnUpdatedToken(const std::string& token);
   virtual void OnPassphraseRequired(bool for_decryption);
   virtual void OnPassphraseFailed();
   virtual void OnPassphraseAccepted(const std::string& bootstrap_token);
   virtual void OnEncryptionComplete(
       const syncable::ModelTypeSet& encrypted_types);
   virtual void OnInitializationComplete();
-  virtual void OnPaused();
-  virtual void OnResumed();
   virtual void OnStopSyncingPermanently();
   virtual void OnClearServerDataSucceeded();
   virtual void OnClearServerDataFailed();
 
  private:
   JsEventRouter* parent_router_;
 
   DISALLOW_COPY_AND_ASSIGN(JsSyncManagerObserver);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_JS_SYNC_MANAGER_OBSERVER_H_