Syncfs-internal: Return empty value if metadata_database is not yet initialized

chrome/browser/sync_file_system/drive_backend/sync_engine.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/sync_engine.h"
 
 #include "base/bind.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/values.h"
 #include "chrome/browser/drive/drive_api_service.h"
@@ skipping 199 matching lines @@
   // TODO(tzik): Implement this before we support manual conflict resolution.
   return false;
 }
 
 RemoteServiceState SyncEngine::GetCurrentState() const {
   return service_state_;
 }
 
 void SyncEngine::GetOriginStatusMap(OriginStatusMap* status_map) {
   DCHECK(status_map);
-  if (!extension_service_)
+  if (!extension_service_ || !metadata_database_)
     return;
 
   std::vector<std::string> app_ids;
   metadata_database_->GetRegisteredAppIDs(&app_ids);
 
   for (std::vector<std::string>::const_iterator itr = app_ids.begin();
        itr != app_ids.end(); ++itr) {
     const std::string& app_id = *itr;
     GURL origin =
         extensions::Extension::GetBaseURLFromExtensionId(app_id);
     (*status_map)[origin] =
         metadata_database_->IsAppEnabled(app_id) ? "Enabled" : "Disabled";
   }
 }
 
 scoped_ptr<base::ListValue> SyncEngine::DumpFiles(const GURL& origin) {
+  if (!metadata_database_)
+    return scoped_ptr<base::ListValue>();
   return metadata_database_->DumpFiles(origin.host());
 }
 
 void SyncEngine::SetSyncEnabled(bool enabled) {
   if (sync_enabled_ == enabled)
     return;
 
   RemoteServiceState old_state = GetCurrentState();
   sync_enabled_ = enabled;
   if (old_state == GetCurrentState())
@@ skipping 339 matching lines @@
         tracker.tracker_kind() == TRACKER_KIND_APP_ROOT;
     if (is_app_enabled && !is_app_root_tracker_enabled)
       EnableOrigin(origin, base::Bind(&EmptyStatusCallback));
     else if (!is_app_enabled && is_app_root_tracker_enabled)
       DisableOrigin(origin, base::Bind(&EmptyStatusCallback));
   }
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system