drive: Do not try to UpdateResource with empty resource ID

chrome/browser/chromeos/drive/sync/entry_update_performer.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/chromeos/drive/sync/entry_update_performer.h"
 
 #include "base/callback_helpers.h"
 #include "base/file_util.h"
 #include "chrome/browser/chromeos/drive/change_list_loader.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
@@ skipping 305 matching lines @@
         base::Bind(&EntryUpdatePerformer::UpdateEntryAfterUpdateResource,
                    weak_ptr_factory_.GetWeakPtr(),
                    context,
                    callback,
                    local_state->entry.local_id(),
                    base::Passed(&loader_lock)));
     return;
   }
 
   // No need to perform update.
-  if (local_state->entry.metadata_edit_state() == ResourceEntry::CLEAN) {
+  if (local_state->entry.metadata_edit_state() == ResourceEntry::CLEAN ||
+      local_state->entry.resource_id().empty()) {
     callback.Run(FILE_ERROR_OK);
     return;
   }
 
-  DCHECK(!local_state->entry.resource_id().empty());
-
   // Perform metadata update.
   scheduler_->UpdateResource(
       local_state->entry.resource_id(), local_state->parent_entry.resource_id(),
       local_state->entry.title(), last_modified, last_accessed,
       context,
       base::Bind(&EntryUpdatePerformer::UpdateEntryAfterUpdateResource,
                  weak_ptr_factory_.GetWeakPtr(),
                  context, callback, local_state->entry.local_id(),
                  base::Passed(scoped_ptr<base::ScopedClosureRunner>())));
 }
@@ skipping 39 matching lines @@
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
 
   if (!changed_directory->empty())
     observer_->OnDirectoryChangedByOperation(*changed_directory);
   callback.Run(error);
 }
 
 }  // namespace internal
 }  // namespace drive