Add the pdf plugin's source in src\pdf.

pdf/pdfium/pdfium_mem_buffer_file_read.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 PDF_PDFIUM_PDFIUM_MEM_BUFFER_FILE_READ_H_
+#define PDF_PDFIUM_PDFIUM_MEM_BUFFER_FILE_READ_H_
+
+#include <stdlib.h>
+
+#include "third_party/pdfium/fpdfsdk/include/fpdfview.h"
+
+namespace chrome_pdf {
+
+// Implementation of FPDF_FILEACCESS from a memory buffer.
+class PDFiumMemBufferFileRead : public FPDF_FILEACCESS {
+ public:
+  PDFiumMemBufferFileRead(const void* data, size_t size);
+  ~PDFiumMemBufferFileRead();
+
+ private:
+  static int GetBlock(void* param,
+                      unsigned long position,
+                      unsigned char* buf,
+                      unsigned long size);
+  const unsigned char* data_;
+};
+
+}  // namespace chrome_pdf
+
+#endif  // PDF_PDFIUM_PDFIUM_MEM_BUFFER_FILE_READ_H_