[SyncFS] Run V2 backend tasks as SyncTask

chrome/browser/sync_file_system/drive_backend/metadata_database_index.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database_index.h"
 
 #include "base/metrics/histogram.h"
 #include "chrome/browser/sync_file_system/drive_backend/drive_backend_constants.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.pb.h"
 
@@ skipping 310 matching lines @@
 void MetadataDatabaseIndex::AddToPathIndexes(
     const FileTracker& new_tracker) {
   int64 parent = new_tracker.parent_tracker_id();
   std::string title = GetTrackerTitle(new_tracker);
 
   DVLOG(3) << "  Add to trackers_by_parent_and_title_: "
            << parent << " " << title;
 
   trackers_by_parent_and_title_[parent][title].Insert(new_tracker);
 
-  if (trackers_by_parent_and_title_[parent][title].size() > 1) {
+  if (trackers_by_parent_and_title_[parent][title].size() > 1 &&
+      !title.empty()) {
     DVLOG_IF(3, !ContainsKey(multi_backing_file_paths_,
                              ParentIDAndTitle(parent, title)))
         << "  Add to multi_backing_file_paths_: " << parent << " " << title;
     multi_backing_file_paths_.insert(ParentIDAndTitle(parent, title));
   }
 }
 
 void MetadataDatabaseIndex::UpdateInPathIndexes(
     const FileTracker& old_tracker,
     const FileTracker& new_tracker) {
@@ skipping 20 matching lines @@
         trackers_by_title->erase(found);
     } else {
       NOTREACHED();
     }
 
     DVLOG(3) << "  Add to trackers_by_parent_and_title_: "
              << parent << " " << title;
 
     (*trackers_by_title)[title].Insert(new_tracker);
 
-    if (trackers_by_parent_and_title_[parent][old_title].size() <= 1) {
+    if (trackers_by_parent_and_title_[parent][old_title].size() <= 1 &&
+        !old_title.empty()) {
       DVLOG_IF(3, ContainsKey(multi_backing_file_paths_,
-                              ParentIDAndTitle(parent, title)))
+                              ParentIDAndTitle(parent, old_title)))
           << "  Remove from multi_backing_file_paths_: "
-          << parent << " " << title;
-      multi_backing_file_paths_.erase(ParentIDAndTitle(parent, title));
+          << parent << " " << old_title;
+      multi_backing_file_paths_.erase(ParentIDAndTitle(parent, old_title));
     }
 
-    if (trackers_by_parent_and_title_[parent][title].size() > 1) {
+    if (trackers_by_parent_and_title_[parent][title].size() > 1 &&
+        !title.empty()) {
       DVLOG_IF(3, !ContainsKey(multi_backing_file_paths_,
                                ParentIDAndTitle(parent, title)))
           << "  Add to multi_backing_file_paths_: " << parent << " " << title;
       multi_backing_file_paths_.insert(ParentIDAndTitle(parent, title));
     }
 
     return;
   }
 
   if (old_tracker.active() && !new_tracker.active())
     trackers_by_parent_and_title_[parent][title].Deactivate(tracker_id);
   else if (!old_tracker.active() && new_tracker.active())
     trackers_by_parent_and_title_[parent][title].Activate(tracker_id);
 }
 
 void MetadataDatabaseIndex::RemoveFromPathIndexes(
     const FileTracker& tracker) {
   int64 tracker_id = tracker.tracker_id();
   int64 parent = tracker.parent_tracker_id();
   std::string title = GetTrackerTitle(tracker);
 
   DCHECK(ContainsKey(trackers_by_parent_and_title_, parent));
   DCHECK(ContainsKey(trackers_by_parent_and_title_[parent], title));
 
   DVLOG(3) << "  Remove from trackers_by_parent_and_title_: "
            << parent << " " << title;
 
   trackers_by_parent_and_title_[parent][title].Erase(tracker_id);
 
-  if (trackers_by_parent_and_title_[parent][title].size() <= 1) {
+  if (trackers_by_parent_and_title_[parent][title].size() <= 1 &&
+      !title.empty()) {
     DVLOG_IF(3, ContainsKey(multi_backing_file_paths_,
                             ParentIDAndTitle(parent, title)))
         << "  Remove from multi_backing_file_paths_: "
         << parent << " " << title;
     multi_backing_file_paths_.erase(ParentIDAndTitle(parent, title));
   }
 
   if (trackers_by_parent_and_title_[parent][title].empty()) {
     trackers_by_parent_and_title_[parent].erase(title);
     if (trackers_by_parent_and_title_[parent].empty())
@@ skipping 45 matching lines @@
 
     DVLOG(3) << "  Remove from dirty_trackers_: " << tracker_id;
     dirty_trackers_.erase(tracker_id);
 
     demoted_dirty_trackers_.erase(tracker_id);
   }
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system