Revert the revert. This change was not the cause of the failures, so relanding.

chrome/browser/sync/engine/all_status.cc

 // 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.
 
 #include "chrome/browser/sync/engine/all_status.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/port.h"
@@ skipping 170 matching lines @@
 void AllStatus::SetCryptographerReady(bool ready) {
   ScopedStatusLock lock(this);
   status_.cryptographer_ready = ready;
 }
 
 void AllStatus::SetCryptoHasPendingKeys(bool has_pending_keys) {
   ScopedStatusLock lock(this);
   status_.crypto_has_pending_keys = has_pending_keys;
 }
 
+void AllStatus::SetUniqueId(const std::string& guid) {
+  ScopedStatusLock lock(this);
+  status_.unique_id = guid;
+}
+
 ScopedStatusLock::ScopedStatusLock(AllStatus* allstatus)
     : allstatus_(allstatus) {
   allstatus->mutex_.Acquire();
 }
 
 ScopedStatusLock::~ScopedStatusLock() {
   allstatus_->CalcStatusChanges();
   allstatus_->mutex_.Release();
 }
 
 }  // namespace browser_sync