[Invalidations] Require there to be no registered handlers on Invalidator destruction

chrome/browser/sync/profile_sync_service.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_PROFILE_SYNC_SERVICE_H_
 #define CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 
 #include <list>
 #include <string>
 
@@ skipping 23 matching lines @@
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_types.h"
 #include "google_apis/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/engine/model_safe_worker.h"
 #include "sync/internal_api/public/sync_manager_factory.h"
 #include "sync/internal_api/public/util/experiments.h"
 #include "sync/internal_api/public/util/unrecoverable_error_handler.h"
 #include "sync/js/sync_js_controller.h"
-#include "sync/notifier/invalidator_registrar.h"
 
 class Profile;
 class ProfileSyncComponentsFactory;
 class SigninManager;
 class SyncGlobalError;
 
 namespace browser_sync {
 class BackendMigrator;
 class ChangeProcessor;
 class DataTypeManager;
 class JsController;
 class SessionModelAssociator;
 
 namespace sessions { class SyncSessionSnapshot; }
 }
 
 namespace syncer {
 class BaseTransaction;
+class InvalidatorRegistrar;
 struct SyncCredentials;
 struct UserShare;
 }
 
 namespace sync_pb {
 class EncryptedData;
 }  // namespace sync_pb
 
 // ProfileSyncService is the layer between browser subsystems like bookmarks,
 // and the sync backend.  Each subsystem is logically thought of as being
@@ skipping 138 matching lines @@
   // Sync server URL for dev channel users
   static const char* kDevServerUrl;
 
   // Takes ownership of |factory|.
   ProfileSyncService(ProfileSyncComponentsFactory* factory,
                      Profile* profile,
                      SigninManager* signin,
                      StartBehavior start_behavior);
   virtual ~ProfileSyncService();
 
-  // Initializes the object. This should be called every time an object of this
-  // class is constructed.
+  // Initializes the object. This must be called at most once, and
+  // immediately after an object of this class is constructed.
   void Initialize();
 
   virtual void SetSyncSetupCompleted();
 
   // ProfileSyncServiceBase implementation.
   virtual bool HasSyncSetupCompleted() const OVERRIDE;
   virtual bool ShouldPushChanges() OVERRIDE;
   virtual syncer::ModelTypeSet GetPreferredDataTypes() const OVERRIDE;
   virtual void AddObserver(Observer* observer) OVERRIDE;
   virtual void RemoveObserver(Observer* observer) OVERRIDE;
@@ skipping 312 matching lines @@
     return configure_status_;
   }
 
   // If true, the ProfileSyncService has detected that a new GAIA signin has
   // succeeded, and is waiting for initialization to complete. This is used by
   // the UI to differentiate between a new auth error (encountered as part of
   // the initialization process) and a pre-existing auth error that just hasn't
   // been cleared yet. Virtual for testing purposes.
   virtual bool waiting_for_auth() const;
 
-  // InvalidationFrontend implementation.
+  // InvalidationFrontend implementation.  It is an error to have
+  // registered handlers when Shutdown() is called.
   virtual void RegisterInvalidationHandler(
       syncer::InvalidationHandler* handler) OVERRIDE;
   virtual void UpdateRegisteredInvalidationIds(
       syncer::InvalidationHandler* handler,
       const syncer::ObjectIdSet& ids) OVERRIDE;
   virtual void UnregisterInvalidationHandler(
       syncer::InvalidationHandler* handler) OVERRIDE;
   virtual syncer::InvalidatorState GetInvalidatorState() const OVERRIDE;
 
-  // ProfileKeyedService implementation.
+  // ProfileKeyedService implementation.  This must be called exactly
+  // once (before this object is destroyed).
   virtual void Shutdown() OVERRIDE;
 
   // Simulate an incoming notification for the given id and payload.
   void EmitInvalidationForTest(
       const invalidation::ObjectId& id,
       const std::string& payload);
 
  protected:
   // Used by test classes that derive from ProfileSyncService.
   virtual browser_sync::SyncBackendHost* GetBackendForTest();
@@ skipping 258 matching lines @@
   // If |true|, there is setup UI visible so we should not start downloading
   // data types.
   bool setup_in_progress_;
 
   // The set of currently enabled sync experiments.
   syncer::Experiments current_experiments;
 
   // Factory the backend will use to build the SyncManager.
   syncer::SyncManagerFactory sync_manager_factory_;
 
-  // Dispatches invalidations to handlers.
-  syncer::InvalidatorRegistrar invalidator_registrar_;
+  // Dispatches invalidations to handlers.  Set in Initialize() and
+  // unset in Shutdown().
+  scoped_ptr<syncer::InvalidatorRegistrar> invalidator_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(
     const syncer::SyncProtocolError& error);
 
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_