[Sync] Fix favicon updates to handle orphan nodes

chrome/browser/sync/glue/favicon_cache.h

 // Copyright (c) 2013 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_FAVICON_CACHE_H_
 #define CHROME_BROWSER_SYNC_GLUE_FAVICON_CACHE_H_
 
 #include <map>
 #include <string>
 
@@ skipping 116 matching lines @@
 
   // Map of favicon url to favicon image.
   typedef std::map<GURL, linked_ptr<SyncedFaviconInfo> > FaviconMap;
   typedef std::set<linked_ptr<SyncedFaviconInfo>,
                    FaviconRecencyFunctor> RecencySet;
   // Map of page url to task id (for favicon loading).
   typedef std::map<GURL, CancelableTaskTracker::TaskId> PageTaskMap;
   // Map of page url to favicon url.
   typedef std::map<GURL, GURL> PageFaviconMap;
 
-  // Enum used to decide which sync datatypes to update on a favicon change.
-  enum SyncState {
-    SYNC_IMAGE,
-    SYNC_TRACKING,
-    SYNC_BOTH
-  };
-
   // Helper method to perform OnReceivedSyncFavicon work without worrying about
   // whether caller holds a sync transaction.
   void OnReceivedSyncFaviconImpl(const GURL& icon_url,
                                  const std::string& icon_bytes,
                                  int64 visit_time_ms);
 
   // Callback method to store a tab's favicon into its sync node once it becomes
   // available. Does nothing if no favicon data was available.
   void OnFaviconDataAvailable(
       const GURL& page_url,
       const std::vector<history::FaviconBitmapResult>& bitmap_result);
 
-  // Helper method to update the sync state of the favicon at |icon_url|.
+  // Helper method to update the sync state of the favicon at |icon_url|. If
+  // either |image_change_type| or |tracking_change_type| is ACTION_INVALID,
+  // the corresponding datatype won't be updated.
   // Note: should only be called after both FAVICON_IMAGES and FAVICON_TRACKING
   // have been successfully set up.
   void UpdateSyncState(const GURL& icon_url,
-                       SyncState state_to_update,
-                       syncer::SyncChange::SyncChangeType change_type);
+                       syncer::SyncChange::SyncChangeType image_change_type,
+                       syncer::SyncChange::SyncChangeType tracking_change_type);
 
   // Helper method to get favicon info from |synced_favicons_|. If no info
   // exists for |icon_url|, creates a new SyncedFaviconInfo in both
   // |synced_favicons_| and |recent_favicons_| and returns it.
   SyncedFaviconInfo* GetFaviconInfo(const GURL& icon_url);
 
   // Updates the last visit time for the favicon at |icon_url| to |time| (and
   // correspondly updates position in |recent_favicons_|.
   void UpdateFaviconVisitTime(const GURL& icon_url, base::Time time);
 
@@ skipping 77 matching lines @@
 
   // Maximum number of favicons to sync. 0 means no limit.
   const size_t max_sync_favicon_limit_;
 
   DISALLOW_COPY_AND_ASSIGN(FaviconCache);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_FAVICON_CACHE_H_