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

pdf/pdfium/pdfium_mem_buffer_file_write.cc

+// 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.
+
+#include "pdf/pdfium/pdfium_mem_buffer_file_write.h"
+
+namespace chrome_pdf {
+
+PDFiumMemBufferFileWrite::PDFiumMemBufferFileWrite() {
+  version = 1;
+  WriteBlock = &WriteBlockImpl;
+}
+
+PDFiumMemBufferFileWrite::~PDFiumMemBufferFileWrite() {
+}
+
+int PDFiumMemBufferFileWrite::WriteBlockImpl(FPDF_FILEWRITE* this_file_write,
+                                             const void* data,
+                                             unsigned long size) {
+  PDFiumMemBufferFileWrite* mem_buffer_file_write =
+      static_cast<PDFiumMemBufferFileWrite*>(this_file_write);
+  return mem_buffer_file_write->DoWriteBlock(data, size);
+}
+
+int PDFiumMemBufferFileWrite::DoWriteBlock(const void* data,
+                                           unsigned long size) {
+  buffer_.append(static_cast<const unsigned char*>(data), size);
+  return 1;
+}
+
+
+}  // namespace chrome_pdf
+