[SyncFS] Handle dirty tracker IDs in MetadataDatabaseIndexOnDisk

chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc

Index: chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc
diff --git a/chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc b/chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc
index 17fedfa890990f5838fd161edd1bc9aefb67bc73..877be12dc5fdadc1a86d877d000bb36a01d5a464 100644
--- a/chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc
+++ b/chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc
@@ -383,7 +383,8 @@ int64 MetadataDatabaseIndex::PickDirtyTracker() const {
   return *dirty_trackers_.begin();
 }
 
-void MetadataDatabaseIndex::DemoteDirtyTracker(int64 tracker_id) {
+void MetadataDatabaseIndex::DemoteDirtyTracker(
+    int64 tracker_id, leveldb::WriteBatch* batch) {

[nhiroki, 2014/07/07 09:52:29]

You may want to clarify that we don't have to use this |batch| here for
maintainability. For example,

void MetadataDatabaseIndex::DemoteDirtyTracker(
  int64 tracker_id, leveldb::WriteBatch* /* unused */) {

or

void MetadataDatabaseIndex::DemoteDirtyTracker(
    int64 tracker_id, leveldb::WriteBatch* batch) {
  // We don't have to add the tracker into |batch|. 

[peria, 2014/07/08 03:05:07]

Done.

   if (dirty_trackers_.erase(tracker_id))
     demoted_dirty_trackers_.insert(tracker_id);
 }
@@ -392,7 +393,8 @@ bool MetadataDatabaseIndex::HasDemotedDirtyTracker() const {
   return !demoted_dirty_trackers_.empty();
 }
 
-void MetadataDatabaseIndex::PromoteDemotedDirtyTrackers() {
+void MetadataDatabaseIndex::PromoteDemotedDirtyTrackers(
+    leveldb::WriteBatch* batch) {

[nhiroki, 2014/07/07 09:52:29]

ditto.

[peria, 2014/07/08 03:05:07]

Done.

   dirty_trackers_.insert(demoted_dirty_trackers_.begin(),
                          demoted_dirty_trackers_.end());
   demoted_dirty_trackers_.clear();