SyncFS: Handle HTTP_CONFLICT as Precondition error

chrome/browser/sync_file_system/drive_backend/conflict_resolver.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/conflict_resolver.h"
 
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "chrome/browser/drive/drive_api_util.h"
@@ skipping 184 matching lines @@
   drive_service()->DeleteResource(
       file_id, etag,
       base::Bind(&ConflictResolver::DidRemoveFile,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback, file_id));
 }
 
 void ConflictResolver::DidRemoveFile(const SyncStatusCallback& callback,
                                      const std::string& file_id,
                                      google_apis::GDataErrorCode error) {
-  if (error == google_apis::HTTP_PRECONDITION) {
+  if (error == google_apis::HTTP_PRECONDITION ||
+      error == google_apis::HTTP_CONFLICT) {
     callback.Run(SYNC_STATUS_RETRY);
     return;
   }
 
   if (error != google_apis::HTTP_SUCCESS &&
       error != google_apis::HTTP_NOT_FOUND) {
     callback.Run(GDataErrorCodeToSyncStatusCode(error));
     return;
   }
 
@@ skipping 14 matching lines @@
   set_used_network(true);
   return sync_context_->GetDriveService();
 }
 
 MetadataDatabase* ConflictResolver::metadata_database() {
   return sync_context_->GetMetadataDatabase();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system