[SyncFS] Unconditionally demote remote file trackers on remote-to-local sync

chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.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/remote_to_local_syncer.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/file_util.h"
 #include "base/format_macros.h"
@@ skipping 111 matching lines @@
     NOTREACHED();
     SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_FAILED);
     return;
   }
 
   dirty_tracker_ = make_scoped_ptr(new FileTracker);
   if (metadata_database()->GetNormalPriorityDirtyTracker(
           dirty_tracker_.get())) {
     token->RecordLog(base::StringPrintf(
         "Start: tracker_id=%" PRId64, dirty_tracker_->tracker_id()));
+    metadata_database()->LowerTrackerPriority(dirty_tracker_->tracker_id());
     ResolveRemoteChange(token.Pass());
     return;
   }
 
   token->RecordLog("Nothing to do.");
   SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_NO_CHANGE_TO_SYNC);
 }
 
 void RemoteToLocalSyncer::ResolveRemoteChange(scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
@@ skipping 195 matching lines @@
 }
 
 void RemoteToLocalSyncer::DidUpdateDatabaseForRemoteMetadata(
     scoped_ptr<SyncTaskToken> token,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
     SyncCompleted(token.Pass(), status);
     return;
   }
 
+  metadata_database()->PromoteDemotedTracker(dirty_tracker_->tracker_id());
+
   // Do not update |dirty_tracker_|.
   SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
 }
 
 void RemoteToLocalSyncer::DidPrepareForAddOrUpdateFile(
     scoped_ptr<SyncTaskToken> token,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
     SyncCompleted(token.Pass(), status);
     return;
@@ skipping 19 matching lines @@
       sync_action_ = SYNC_ACTION_UPDATED;
       // Download the file and overwrite the existing local file.
       DownloadFile(token.Pass());
       return;
     }
 
     DCHECK_EQ(SYNC_FILE_TYPE_DIRECTORY, local_metadata_->file_type);
 
     // Got a remote regular file modification for existing local folder.
     // Our policy prioritize folders in this case.
-    // Lower the priority of the tracker to prevent repeated remote sync to the
-    // same tracker, and let local-to-remote sync phase process this change.
-    metadata_database()->LowerTrackerPriority(dirty_tracker_->tracker_id());
+    // Let local-to-remote sync phase process this change.
     remote_change_processor()->RecordFakeLocalChange(
         url_,
         FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE,
                    local_metadata_->file_type),
         SyncCompletedCallback(token.Pass()));
     return;
   }
 
   DCHECK(local_changes_->back().IsAddOrUpdate());
   // Conflict case.
   // Do nothing for the change now, and handle this in LocalToRemoteSync phase.
-
-  // Lower the priority of the tracker to prevent repeated remote sync to the
-  // same tracker.
-  metadata_database()->LowerTrackerPriority(dirty_tracker_->tracker_id());
   SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
 }
 
 void RemoteToLocalSyncer::HandleFolderUpdate(
     scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
   DCHECK(dirty_tracker_->active());
   DCHECK(!HasDisabledAppRoot(metadata_database(), *dirty_tracker_));
 
   DCHECK(remote_metadata_);
@@ skipping 307 matching lines @@
 
   base::FilePath path = file.path();
   const std::string md5 = drive::util::GetMd5Digest(path);
   if (md5.empty()) {
     SyncCompleted(token.Pass(), SYNC_FILE_ERROR_NOT_FOUND);
     return;
   }
 
   if (md5 != remote_metadata_->details().md5()) {
     // File has been modified since last metadata retrieval.
-
-    // Lower the priority of the tracker to prevent repeated remote sync to the
-    // same tracker.
-    metadata_database()->LowerTrackerPriority(dirty_tracker_->tracker_id());
     SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
     return;
   }
 
   remote_change_processor()->ApplyRemoteChange(
       FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE, SYNC_FILE_TYPE_FILE),
       path, url_,
       base::Bind(&RemoteToLocalSyncer::DidApplyDownload,
                  weak_ptr_factory_.GetWeakPtr(),
                  base::Passed(&token), base::Passed(&file)));
 }
 
 void RemoteToLocalSyncer::DidApplyDownload(scoped_ptr<SyncTaskToken> token,
                                            webkit_blob::ScopedFile,
                                            SyncStatusCode status) {
-  if (status != SYNC_STATUS_OK)
-    metadata_database()->LowerTrackerPriority(dirty_tracker_->tracker_id());
   SyncCompleted(token.Pass(), status);
 }
 
 void RemoteToLocalSyncer::CreateFolder(scoped_ptr<SyncTaskToken> token) {
   remote_change_processor()->ApplyRemoteChange(
       FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE,
                  SYNC_FILE_TYPE_DIRECTORY),
       base::FilePath(), url_,
       SyncCompletedCallback(token.Pass()));
 }
@@ skipping 13 matching lines @@
 
 SyncStatusCallback RemoteToLocalSyncer::SyncCompletedCallback(
     scoped_ptr<SyncTaskToken> token) {
   return base::Bind(&RemoteToLocalSyncer::SyncCompleted,
                     weak_ptr_factory_.GetWeakPtr(),
                     base::Passed(&token));
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system