[SyncFS] Make DumpFiles async

chrome/browser/sync_file_system/sync_file_system_service.cc

 // Copyright (c) 2012 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/sync_file_system_service.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/format_macros.h"
@@ skipping 495 matching lines @@
     const DumpFilesCallback& callback,
     SyncStatusCode status) {
   DCHECK(!origin.is_empty());
 
   if (status != SYNC_STATUS_OK) {
     base::ListValue empty_result;
     callback.Run(&empty_result);
     return;
   }
 
-  base::ListValue* files =
-      GetRemoteService(origin)->DumpFiles(origin).release();
+  GetRemoteService(origin)->DumpFiles(
+      origin,
+      base::Bind(
+          &SyncFileSystemService::DidDumpFiles,
+          AsWeakPtr(),
+          origin,
+          callback));
+}
+
+void SyncFileSystemService::DidDumpFiles(
+    const GURL& origin,
+    const DumpFilesCallback& callback,
+    scoped_ptr<base::ListValue> dump_files) {
+  base::ListValue* files = dump_files.release();
   if (!files) {
     callback.Run(new base::ListValue);
     return;
   }
 
   if (!files->GetSize()) {
     callback.Run(files);
     return;
   }
 
@@ skipping 248 matching lines @@
     v2_remote_service_->SetRemoteChangeProcessor(local_service_.get());
     v2_remote_service_->SetSyncEnabled(sync_enabled_);
     v2_remote_service_->SetDefaultConflictResolutionPolicy(
         remote_service_->GetDefaultConflictResolutionPolicy());
     remote_sync_runners_.push_back(v2_remote_syncer.release());
   }
   return v2_remote_service_.get();
 }
 
 }  // namespace sync_file_system