[SyncFS] Force activate folder tracker on folder creation conflict case

chrome/browser/sync_file_system/drive_backend/metadata_database.cc

 // Copyright 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.
 
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database.h"
 
 #include <algorithm>
 #include <stack>
 
 #include "base/bind.h"
@@ skipping 1015 matching lines @@
       continue;
 
     if (candidate->has_synced_details() &&
         candidate->synced_details().title() != title)
       continue;
     tracker = candidate;
   }
 
   DCHECK(tracker);
 
+  if (!tracker->active() && same_file_id.has_active())
+    return ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER;
+
+  scoped_ptr<leveldb::WriteBatch> batch(new leveldb::WriteBatch);
+
   if (!tracker->active()) {
-    if (same_file_id.has_active())
-      return ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER;
-
     TrackerSet same_title;
     FindTrackersByParentAndTitle(parent_tracker_id, title, &same_title);
-    if (same_title.has_active())
-      return ACTIVATION_FAILED_SAME_PATH_TRACKER;
+    if (same_title.has_active()) {

[kinuko, 2014/02/06 09:48:01]

Does it make sense to have some comment here? It's cryptic why we're doing this
without context. Something like

'This tracker's status should be resolved when next remote change's fetched and
synced. Mark this inactive for now so that the new one can become active'

[tzik, 2014/02/07 04:43:53]

Added some comment around here.

+      MakeTrackerInactive(same_title.active_tracker()->tracker_id(),
+                          batch.get());
+    }
   }
 
-  scoped_ptr<leveldb::WriteBatch> batch(new leveldb::WriteBatch);
   if (!tracker->has_synced_details() ||
       tracker->synced_details().title() != title) {
     trackers_by_parent_and_title_[parent_tracker_id]
         [GetTrackerTitle(*tracker)].Erase(tracker);
     trackers_by_parent_and_title_[parent_tracker_id][title].Insert(
         tracker);
   }
   *tracker->mutable_synced_details() = file.details();
 
   MakeTrackerActive(tracker->tracker_id(), batch.get());
@@ skipping 990 matching lines @@
     MakeTrackerActive(tracker->tracker_id(), batch);
     ClearDirty(tracker, batch);
     return;
   }
 
   NOTREACHED();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system