[Sync] Avoid ObserverListThreadSafe in ChromeSyncNotificationBridge

chrome/browser/sync/glue/sync_backend_host.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 CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread.h"
 #include "chrome/browser/sync/glue/backend_data_type_configurer.h"
 #include "chrome/browser/sync/glue/chrome_extensions_activity_monitor.h"
-#include "chrome/browser/sync/glue/chrome_sync_notification_bridge.h"
 #include "chrome/common/net/gaia/google_service_auth_error.h"
 #include "googleurl/src/gurl.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/configure_reason.h"
 #include "sync/internal_api/public/engine/model_safe_worker.h"
 #include "sync/internal_api/public/sessions/sync_session_snapshot.h"
 #include "sync/internal_api/public/sync_manager.h"
 #include "sync/internal_api/public/util/report_unrecoverable_error_function.h"
 #include "sync/internal_api/public/util/unrecoverable_error_handler.h"
 #include "sync/internal_api/public/util/weak_handle.h"
 #include "sync/notifier/sync_notifier_factory.h"
 #include "sync/protocol/encryption.pb.h"
 #include "sync/protocol/sync_protocol_error.h"
 
 class MessageLoop;
 class Profile;
 
 namespace syncer {
 class SyncManagerFactory;
 }
 
 namespace browser_sync {
 
 class ChangeProcessor;
+class ChromeSyncNotificationBridge;
 struct Experiments;
 class InvalidatorStorage;
 class JsBackend;
 class JsEventHandler;
 class SyncBackendRegistrar;
 class SyncPrefs;
 
 // SyncFrontend is the interface used by SyncBackendHost to communicate with
 // the entity that created it and, presumably, is interested in sync-related
 // activity.
@@ skipping 416 matching lines @@
   // Name used for debugging (set from profile_->GetDebugName()).
   const std::string name_;
 
   // Our core, which communicates directly to the syncapi.
   scoped_refptr<Core> core_;
 
   InitializationState initialization_state_;
 
   const base::WeakPtr<SyncPrefs> sync_prefs_;
 
-  // A thread-safe listener for handling notifications triggered by
-  // chrome events.
-  ChromeSyncNotificationBridge chrome_sync_notification_bridge_;
+  // A bridge that converts Chrome notifications (on the UI thread)
+  // into invalidations (on the sync thread).
+  scoped_ptr<ChromeSyncNotificationBridge> chrome_sync_notification_bridge_;
 
   syncer::SyncNotifierFactory sync_notifier_factory_;
 
   ChromeExtensionsActivityMonitor extensions_activity_monitor_;
 
   scoped_ptr<SyncBackendRegistrar> registrar_;
 
   // The frontend which we serve (and are owned by).
   SyncFrontend* frontend_;
 
   // We cache the cryptographer's pending keys whenever NotifyPassphraseRequired
   // is called. This way, before the UI calls SetDecryptionPassphrase on the
   // syncer, it can avoid the overhead of an asynchronous decryption call and
   // give the user immediate feedback about the passphrase entered by first
   // trying to decrypt the cached pending keys on the UI thread. Note that
   // SetDecryptionPassphrase can still fail after the cached pending keys are
   // successfully decrypted if the pending keys have changed since the time they
   // were cached.
   sync_pb::EncryptedData cached_pending_keys_;
 
   // UI-thread cache of the last SyncSessionSnapshot received from syncapi.
   syncer::sessions::SyncSessionSnapshot last_snapshot_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHost);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_