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

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 475d56933053765ad2f460b8ca1d7a89df84a095..39414d1fe2c55bbea2e6b72876419322674e87b3 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1106,7 +1106,10 @@ void PDFiumEngine::OnDocumentComplete() {
 }
 
 void PDFiumEngine::OnDocumentCanceled() {
-  OnDocumentComplete();
+  if (visible_pages_.empty())
+    client_->DocumentLoadFailed();
+  else
+    OnDocumentComplete();
 }
 
 void PDFiumEngine::CancelBrowserDownload() {