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

pdf/pdfium/pdfium_engine.cc

 // 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.
 
 #include "pdf/pdfium/pdfium_engine.h"
 
 #include <math.h>
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1088 matching lines @@
   }
   file_access_.m_FileLen = doc_loader_->GetDocumentSize();
   if (!fpdf_availability_) {
     fpdf_availability_ = FPDFAvail_Create(&file_availability_, &file_access_);
     DCHECK(fpdf_availability_);
   }
   LoadDocument();
 }
 
 void PDFiumEngine::OnDocumentCanceled() {
-  OnDocumentComplete();

[Lei Zhang, 2016/11/08 01:28:10]

I defer to spelchat / art-snake on this.

[raymes, 2016/11/08 06:00:01]

Sure. Without this the client was never notified that the document load failed.
Also I'm unsure what the benefit is of calling OnDocumentComplete() is here but
I might be missing something.

[snake, 2016/11/08 15:11:25]

Loading of the document may be canceled (by user or other) at moment, when pages
needs for him already loaded. And if we call DocumentLoadFailed, he will se only
error message after that. But i think, we should allow him to use already loaded
pages in this case.

[spelchat, 2016/11/08 17:53:33]

Yeah thinking about it, maybe the noisy failure (DocumentLoadFailed) is better.
It's unfortunate that the user could potentially be able to view a few pages if
we didn't display an error, but it seems preferable to showing a partially
loaded document without mentioning that loading the document failed (and
refreshing the page would potentially fix the issue).

FWIW I don't think the user can cancel loading the document, short of pulling
out the plug (there's no button to stop loading the page for PDFs AFAIK), so if
OnDocumentCanceled is called, the user isn't likely to know the page load was
canceled.

+  client_->DocumentLoadFailed();
 }
 
 void PDFiumEngine::CancelBrowserDownload() {
   client_->CancelBrowserDownload();
 }
 
 void PDFiumEngine::FinishLoadingDocument() {
   DCHECK(doc_loader_->IsDocumentComplete() && doc_);
 
   if (!form_) {
@@ skipping 2905 matching lines @@
   FPDF_DOCUMENT doc =
       FPDF_LoadMemDocument(pdf_buffer, pdf_buffer_size, nullptr);
   if (!doc)
     return false;
   bool success = FPDF_GetPageSizeByIndex(doc, page_number, width, height) != 0;
   FPDF_CloseDocument(doc);
   return success;
 }
 
 }  // namespace chrome_pdf