[Sync] Fix encryption/passphrase handling.

chrome/browser/sync/profile_sync_service.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_PROFILE_SYNC_SERVICE_H_
 #define CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 613 matching lines @@
   ClearServerDataState clear_server_data_state_;
 
   // Timeout for the clear data command.  This timeout is a temporary hack
   // and is necessary because the nudge sync framework can drop nudges for
   // a wide variety of sync-related conditions (throttling, connections issues,
   // syncer paused, etc.).  It can only be removed correctly when the framework
   // is reworked to allow one-shot commands like clearing server data.
   base::OneShotTimer<ProfileSyncService> clear_server_data_timer_;
 
   // The most recently requested set of types to encrypt. Set by the user,
-  // and cached if the syncer was unable to encrypt new types (for example
-  // because we haven't finished initializing). Cleared when we successfully
-  // post a new encrypt task to the sync backend.
+  // and cached until the syncer either finishes encryption
+  // (OnEncryptionComplete) or the user cancels.
   syncable::ModelTypeSet pending_types_for_encryption_;
 
   scoped_ptr<browser_sync::BackendMigrator> migrator_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_