Cull autofill entries older than 60 days.

chrome/browser/webdata/autocomplete_syncable_service.cc

Index: chrome/browser/webdata/autocomplete_syncable_service.cc
diff --git a/chrome/browser/webdata/autocomplete_syncable_service.cc b/chrome/browser/webdata/autocomplete_syncable_service.cc
index af1cde14a5b5d40e0d27e42a3d6dcf4f89693d82..0732a582e08c3efb351d77d6a6826e65a6925f73 100644
--- a/chrome/browser/webdata/autocomplete_syncable_service.cc
+++ b/chrome/browser/webdata/autocomplete_syncable_service.cc
@@ -108,16 +108,41 @@ SyncError AutocompleteSyncableService::MergeDataAndStartSyncing(
     CreateOrUpdateEntry(*sync_iter, &new_db_entries, &new_synced_entries);
   }
 
+  // Check if newly received items need culling.
+  bool need_to_cull_data = false;
+  for (size_t i = 0; i < new_synced_entries.size() && !need_to_cull_data; ++i) {
+    if (new_synced_entries[i].IsExpired())
+      need_to_cull_data = true;
+  }
+
   if (!SaveChangesToWebData(new_synced_entries))
     return SyncError(FROM_HERE, "Failed to update webdata.", model_type());
 
   WebDataService::NotifyOfMultipleAutofillChanges(web_data_service_);
+  keys_to_ignore_.clear();
 
   SyncChangeList new_changes;
   for (AutocompleteEntryMap::iterator i = new_db_entries.begin();
        i != new_db_entries.end(); ++i) {
-    new_changes.push_back(
-        SyncChange(i->second.first, CreateSyncData(*(i->second.second))));
+    // Sync back only the data that appeared after
+    // |AutofillEntry::ExpirationTime()|.
+    if (!i->second.second->IsExpired()) {
+      new_changes.push_back(
+          SyncChange(i->second.first, CreateSyncData(*(i->second.second))));
+    } else {
+      need_to_cull_data = true;
+      // Key is not on the server and is too old, it will not ever be synced -
+      // delete it locally.
+      if (i->second.first == SyncChange::ACTION_ADD)
+        keys_to_ignore_.insert(i->first);
+    }
+  }
+
+  if (need_to_cull_data) {
+    // This will schedule deletion operation later on DB thread and we will
+    // be notified on the results of the deletion and deletes will be synced to
+    // the sync.
+    web_data_service_->RemoveExpiredFormElements();
   }
 
   SyncError error = sync_processor_->ProcessSyncChanges(FROM_HERE, new_changes);
@@ -357,10 +382,12 @@ void AutocompleteSyncableService::ActOnChanges(
         break;
       }
       case AutofillChange::REMOVE: {
-        std::vector<base::Time> timestamps;
-        AutofillEntry entry(change->key(), timestamps);
-        new_changes.push_back(SyncChange(SyncChange::ACTION_DELETE,
-                                         CreateSyncData(entry)));
+        if (keys_to_ignore_.find(change->key()) == keys_to_ignore_.end()) {
+          std::vector<base::Time> timestamps;
+          AutofillEntry entry(change->key(), timestamps);
+          new_changes.push_back(SyncChange(SyncChange::ACTION_DELETE,
+                                           CreateSyncData(entry)));
+        }
         break;
       }
       default:
@@ -374,6 +401,8 @@ void AutocompleteSyncableService::ActOnChanges(
                   << " Failed processing change:"
                   << " Error:" << error.message();
   }
+  // |keys_to_ignore_| are only needed for the very first notification.
+  keys_to_ignore_.clear();
 }
 
 SyncData AutocompleteSyncableService::CreateSyncData(