[Sync] Make BackendMigrator not wait for full sync cycles

chrome/browser/sync/glue/sync_backend_host.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_GLUE_SYNC_BACKEND_HOST_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 547 matching lines @@
   // For convenience, checks if initialization state is INITIALIZED.
   bool initialized() const { return initialization_state_ == INITIALIZED; }
 
   // A thread where all the sync operations happen.
   base::Thread sync_thread_;
 
   // A reference to the MessageLoop used to construct |this|, so we know how
   // to safely talk back to the SyncFrontend.
   MessageLoop* const frontend_loop_;
 
-  Profile* profile_;
+  Profile* const profile_;
+
+  // Name used for debugging (set from profile_->GetDebugName()).
+  const std::string name_;
 
   sync_notifier::SyncNotifierFactory sync_notifier_factory_;
 
   // This is state required to implement ModelSafeWorkerRegistrar.
   struct {
     // We maintain ownership of all workers.  In some cases, we need to ensure
     // shutdown occurs in an expected sequence by Stop()ing certain workers.
     // They are guaranteed to be valid because we only destroy elements of
     // |workers_| after the syncapi has been destroyed.  Unless a worker is no
     // longer needed because all types that get routed to it have been disabled
@@ skipping 33 matching lines @@
 
   // UI-thread cache of the last SyncSessionSnapshot received from syncapi.
   scoped_ptr<sessions::SyncSessionSnapshot> last_snapshot_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHost);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_