Add RequestOSFileHandle as a private PPAPI

ppapi/thunk/ppb_file_io_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.
 
 #ifndef PPAPI_THUNK_PPB_FILE_IO_API_H_
 #define PPAPI_THUNK_PPB_FILE_IO_API_H_
 
 #include "base/memory/ref_counted.h"
 #include "ppapi/c/ppb_file_io.h"
+#include "ppapi/c/private/pp_file_handle.h"
 #include "ppapi/thunk/ppapi_thunk_export.h"
 
 namespace ppapi {
 
 class TrackedCallback;
 
 namespace thunk {
 
 class PPAPI_THUNK_EXPORT PPB_FileIO_API {
  public:
@@ skipping 24 matching lines @@
   virtual int32_t Flush(scoped_refptr<TrackedCallback> callback) = 0;
   virtual void Close() = 0;
 
   // Trusted API.
   virtual int32_t GetOSFileDescriptor() = 0;
   virtual int32_t WillWrite(int64_t offset,
                             int32_t bytes_to_write,
                             scoped_refptr<TrackedCallback> callback) = 0;
   virtual int32_t WillSetLength(int64_t length,
                                 scoped_refptr<TrackedCallback> callback) = 0;
+
+  // Private API.
+  virtual int32_t GetOSFileHandle(
+      PP_FileHandle* handle,
+      scoped_refptr<TrackedCallback> callback) = 0;
 };
 
 }  // namespace thunk
 }  // namespace ppapi
 
 #endif  // PPAPI_THUNK_PPB_FILE_IO_API_H_