Make Isolated file system writable only if it is configured so

webkit/fileapi/isolated_mount_point_provider.h

 // 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.
 
 #ifndef WEBKIT_FILEAPI_ISOLATED_MOUNT_POINT_PROVIDER_H_
 #define WEBKIT_FILEAPI_ISOLATED_MOUNT_POINT_PROVIDER_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 40 matching lines @@
     const GURL& url,
     int64 offset,
     FileSystemContext* context) const OVERRIDE;
   virtual FileStreamWriter* CreateFileStreamWriter(
     const GURL& url,
     int64 offset,
     FileSystemContext* context) const OVERRIDE;
   virtual FileSystemQuotaUtil* GetQuotaUtil() OVERRIDE;
 
  private:
-  IsolatedContext* isolated_context() const;
-  FilePath GetPathFromURL(const GURL& url) const;
-
   scoped_ptr<IsolatedFileUtil> isolated_file_util_;
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_ISOLATED_MOUNT_POINT_PROVIDER_H_