Remove ENABLE(FILE_SYSTEM) compile-time flag.

Source/WebCore/Modules/filesystem/DOMWindowFileSystem.h

 /*
  * Copyright (C) 2012, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  * DAMAGE.
  */
 
 #ifndef DOMWindowFileSystem_h
 #define DOMWindowFileSystem_h
 
-#if ENABLE(FILE_SYSTEM)
-
 #include <wtf/PassRefPtr.h>
 #include <wtf/text/WTFString.h>
 
 namespace WebCore {
 
 class DOMWindow;
 class EntryCallback;
 class ErrorCallback;
 class FileSystemCallback;
 
@@ skipping 10 matching lines @@
         PERSISTENT,
     };
 
 private:
     DOMWindowFileSystem();
     ~DOMWindowFileSystem();
 };
 
 } // namespace WebCore
 
-#endif // ENABLE(FILE_SYSTEM)
-
 #endif // DOMWindowFileSystem_h