Add test to ensure that URLs that redirect inside the PDF plugin fail to load

pdf/pdfium/pdfium_engine.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_ENGINE_H_
 #define PDF_PDFIUM_PDFIUM_ENGINE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 100 matching lines @@
   bool IsProgressiveLoad() override;
   std::string GetMetadata(const std::string& key) override;
 
   // DocumentLoader::Client implementation.
   pp::Instance* GetPluginInstance() override;
   pp::URLLoader CreateURLLoader() override;
   void OnPartialDocumentLoaded() override;
   void OnPendingRequestComplete() override;
   void OnNewDataAvailable() override;
   void OnDocumentComplete() override;
+  void DocumentLoadFailed() override;
 
   void UnsupportedFeature(int type);
   void FontSubstituted();
 
   std::string current_find_text() const { return current_find_text_; }
 
   FPDF_DOCUMENT doc() { return doc_; }
   FPDF_FORMHANDLE form() { return form_; }
 
  private:
@@ skipping 657 matching lines @@
   bool GetPDFPageSizeByIndex(const void* pdf_buffer,
                              int pdf_buffer_size,
                              int page_number,
                              double* width,
                              double* height) override;
 };
 
 }  // namespace chrome_pdf
 
 #endif  // PDF_PDFIUM_PDFIUM_ENGINE_H_