sync: Track validity of about:sync fields

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 272 matching lines @@
   // Called when a user chooses which data types to sync as part of the sync
   // setup wizard.  |sync_everything| represents whether they chose the
   // "keep everything synced" option; if true, |chosen_types| will be ignored
   // and all data types will be synced.  |sync_everything| means "sync all
   // current and future data types."
   virtual void OnUserChoseDatatypes(bool sync_everything,
       syncer::ModelTypeSet chosen_types);
 
   // Get various information for displaying in the user interface.
   std::string QuerySyncStatusSummary();
-  virtual browser_sync::SyncBackendHost::Status QueryDetailedSyncStatus();
+
+  // Initializes a struct of status indicators with data from the backend.
+  // Returns false if the backend was not available for querying; in that case
+  // the struct will be filled with default data.
+  virtual bool QueryDetailedSyncStatus(
+      browser_sync::SyncBackendHost::Status* result);
 
   virtual const GoogleServiceAuthError& GetAuthError() const;
 
   // Returns true if initial sync setup is in progress (does not return true
   // if the user is customizing sync after already completing setup once).
   // ProfileSyncService uses this to determine if it's OK to start syncing, or
   // if the user is still setting up the initial sync configuration.
   virtual bool FirstSetupInProgress() const;
 
   // Called by the UI to notify the ProfileSyncService that UI is visible so it
@@ skipping 508 matching lines @@
   syncer::SyncManagerFactory sync_manager_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(
     const syncer::SyncProtocolError& error);
 
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_