Remove partially implemented PDF FFI_* handlers

pdf/pdfium/pdfium_engine.cc

Index: pdf/pdfium/pdfium_engine.cc
diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
index b4c07e8478a8fd659955c72aee2a7d47c3d66268..bc13cb79395ec446b72f9348234189a0c9fe40b5 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -876,47 +876,18 @@ void PDFiumEngine::Form_UploadTo(FPDF_FORMFILLINFO* param,
 
 FPDF_LPFILEHANDLER PDFiumEngine::Form_DownloadFromURL(FPDF_FORMFILLINFO* param,
                                                       FPDF_WIDESTRING url) {
-  std::string url_str =
-      base::UTF16ToUTF8(reinterpret_cast<const base::char16*>(url));
-
-  // Now should get data from url.
-  // For testing purpose, use data read from file
-  // TODO: needs the full implementation here
-  FILE* file = fopen(XFA_TESTFILE("downloadtest.tem"), "w");
-
-  FPDF_FILE* file_wrapper = new FPDF_FILE;
-  file_wrapper->file = file;
-  file_wrapper->file_handler.clientData = file_wrapper;
-  file_wrapper->file_handler.Flush = Sample_Flush;
-  file_wrapper->file_handler.GetSize = Sample_GetSize;
-  file_wrapper->file_handler.ReadBlock = Sample_ReadBlock;
-  file_wrapper->file_handler.Release = Sample_Release;
-  file_wrapper->file_handler.Truncate = Sample_Truncate;
-  file_wrapper->file_handler.WriteBlock = Sample_WriteBlock;
-
-  return &file_wrapper->file_handler;
+  // NOTE: Think hard about the security implications before allowing
+  // a PDF file to perform this action.
+  return nullptr;
 }
 
 FPDF_FILEHANDLER* PDFiumEngine::Form_OpenFile(FPDF_FORMFILLINFO* param,
                                               int file_flag,
                                               FPDF_WIDESTRING url,
                                               const char* mode) {
-  std::string url_str = url ?
-      base::UTF16ToUTF8(reinterpret_cast<const base::char16*>(url)) : "NULL";
-
-  // TODO: need to implement open file from the url
-  // Use a file path for the ease of testing
-  FILE* file = fopen(XFA_TESTFILE("tem.txt"), mode);
-  FPDF_FILE* file_wrapper = new FPDF_FILE;
-  file_wrapper->file = file;
-  file_wrapper->file_handler.clientData = file_wrapper;
-  file_wrapper->file_handler.Flush = Sample_Flush;
-  file_wrapper->file_handler.GetSize = Sample_GetSize;
-  file_wrapper->file_handler.ReadBlock = Sample_ReadBlock;
-  file_wrapper->file_handler.Release = Sample_Release;
-  file_wrapper->file_handler.Truncate = Sample_Truncate;
-  file_wrapper->file_handler.WriteBlock = Sample_WriteBlock;
-  return &file_wrapper->file_handler;
+  // NOTE: Think hard about the security implications before allowing
+  // a PDF file to perform this action.
+  return nullptr;
 }
 
 void PDFiumEngine::Form_GotoURL(FPDF_FORMFILLINFO* param,