[SyncFS] Make DumpFiles async

chrome/browser/ui/webui/sync_file_system_internals/file_metadata_handler.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_SYNC_FILE_SYSTEM_INTERNALS_FILE_METADATA_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SYNC_FILE_SYSTEM_INTERNALS_FILE_METADATA_HANDLER_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 14 matching lines @@
   explicit FileMetadataHandler(Profile* profile);
   virtual ~FileMetadataHandler();
 
   // WebUIMessageHandler implementation.
   virtual void RegisterMessages() OVERRIDE;
 
  private:
   void GetExtensions(const base::ListValue* args);
 
   void GetFileMetadata(const base::ListValue* args);
-  void DidGetFileMetadata(const base::ListValue* files);
+  void DidGetFileMetadata(const base::ListValue& files);
 
   Profile* profile_;
   base::WeakPtrFactory<FileMetadataHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FileMetadataHandler);
 };
 }  // namespace syncfs_internals
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SYNC_FILE_SYSTEM_INTERNALS_FILE_METADATA_HANDLER_H_