Switch to standard integer types in pdf/.

pdf/pdfium/pdfium_mem_buffer_file_write.h

 // Copyright (c) 2010 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 PDF_PDFIUM_PDFIUM_MEM_BUFFER_FILE_WRITE_
 #define PDF_PDFIUM_PDFIUM_MEM_BUFFER_FILE_WRITE_
 
+#include <stddef.h>
+
 #include <string>
 
 #include "third_party/pdfium/public/fpdf_save.h"
 
 namespace chrome_pdf {
 
 // Implementation of FPDF_FILEWRITE into a memory buffer.
 class PDFiumMemBufferFileWrite : public FPDF_FILEWRITE {
  public:
   PDFiumMemBufferFileWrite();
   ~PDFiumMemBufferFileWrite();
 
   const std::basic_string<unsigned char>& buffer() { return buffer_; }
   size_t size() { return buffer_.size(); }
 
  private:
   int DoWriteBlock(const void* data, unsigned long size);
   static int WriteBlockImpl(FPDF_FILEWRITE* this_file_write, const void* data,
                             unsigned long size);
 
   std::basic_string<unsigned char> buffer_;
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_PDFIUM_PDFIUM_MEM_BUFFER_FILE_WRITE_