Add XFA pdfium fuzzer

pdf/pdfium/fuzzers/pdfium_xfa_fuzzer.cc

+// Copyright 2017 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/fuzzers/pdfium_fuzzer_helper.h"
+
+class PDFiumXFAFuzzer : public PDFiumFuzzerHelper {
+ public:
+  PDFiumXFAFuzzer() : PDFiumFuzzerHelper() {}
+  ~PDFiumXFAFuzzer() override {}
+
+  int GetFormCallbackVersion() const override { return 2; }
+
+  // Return false if XFA doesn't load as otherwise we're duplicating the work
+  // done by the non-xfa fuzzer.
+  bool OnFormFillEnvLoaded(FPDF_DOCUMENT doc) override {
+    int doc_type = DOCTYPE_PDF;
+    if (!FPDF_HasXFAField(doc, &doc_type) || doc_type == DOCTYPE_PDF)
+      return false;
+    return FPDF_LoadXFA(doc);
+  }
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  PDFiumXFAFuzzer fuzzer;
+  fuzzer.RenderPdf(reinterpret_cast<const char*>(data), size);
+  return 0;
+}