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

chrome/browser/sync_file_system/drive_backend/metadata_database.h

Index: chrome/browser/sync_file_system/drive_backend/metadata_database.h
diff --git a/chrome/browser/sync_file_system/drive_backend/metadata_database.h b/chrome/browser/sync_file_system/drive_backend/metadata_database.h
index 5cd673cc9f3a8222eb7c78815d91c8b3860e9359..74a02f63b902993b83065115fd5237a741e06172 100644
--- a/chrome/browser/sync_file_system/drive_backend/metadata_database.h
+++ b/chrome/browser/sync_file_system/drive_backend/metadata_database.h
@@ -125,7 +125,6 @@ class MetadataDatabase {
   enum ActivationStatus {
     ACTIVATION_PENDING,
     ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER,
-    ACTIVATION_FAILED_SAME_PATH_TRACKER,
   };
 
   enum UpdateOption {
@@ -305,13 +304,11 @@ class MetadataDatabase {
                      const SyncStatusCallback& callback);
 
   // Returns ACTIVATION_PENDING if a tracker of the file can be safely activated
-  // without deactivating any other trackers.  In this case, tries to activate
-  // the tracker, and invokes |callback| upon completion.
+  // without deactivating any other path trackers.  In this case, tries to

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

We never used the term 'path tracker', it's bit unclear

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

Revised these comment.

+  // activate the tracker, and invokes |callback| upon completion.
   // Returns ACTIVATION_FAILED_ANOTHER_ACTIVE_TRACKER if there's another active
   // tracker that tracks |file_id|.
-  // Returns ACTIVATION_FAILED_SAME_PATH_TRACKER if there's another active
-  // tracker that has the same parent tracker and title to |file_id|.
-  // In these FAILED cases, |callback| is not invoked.
+  // In the FAILED case, |callback| is not invoked.

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

nit/suggestion: remove the line-break at the end of line 310, and change the
line 311 to just tell: '|callback| is not invoked in this case'

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

Done.

   ActivationStatus TryNoSideEffectActivation(

[nhiroki, 2014/02/06 10:02:42]

Can we reconsider this function name? In a specific case this deactivates a
tracker (that is "SideEffect)".

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

Done.

       int64 parent_tracker_id,
       const std::string& file_id,