Remove #pragma once from chrome/browser/extensions

chrome/browser/extensions/api/media_gallery/media_gallery_api.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.
 
 // Defines the Chrome Extensions Media Galleries API functions for accessing
 // user's media files, as specified in the extension API JSON.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERY_MEDIA_GALLERY_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERY_MEDIA_GALLERY_API_H_
-#pragma once
 
 #include "chrome/browser/extensions/extension_function.h"
 
 namespace extensions {
 
 class GetMediaFileSystemsFunction : public SyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION_NAME(
       "experimental.mediaGalleries.getMediaFileSystems")
 
@@ skipping 18 matching lines @@
       "experimental.mediaGalleries.assembleMediaFile")
 
  protected:
   virtual ~AssembleMediaFileFunction();
   virtual bool RunImpl() OVERRIDE;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERY_MEDIA_GALLERY_API_H_