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

pdf/out_of_process_instance.cc

Index: pdf/out_of_process_instance.cc
diff --git a/pdf/out_of_process_instance.cc b/pdf/out_of_process_instance.cc
index eb1c17a022a4d67a78c2a5c83f29e1c109e630a3..7063907677af42a5967a64b42ca863ff26faf615 100644
--- a/pdf/out_of_process_instance.cc
+++ b/pdf/out_of_process_instance.cc
@@ -846,15 +846,8 @@ void OutOfProcessInstance::OnPaint(
 }
 
 void OutOfProcessInstance::DidOpen(int32_t result) {
-  if (result == PP_OK) {
-    if (!engine_->HandleDocumentLoad(embed_loader_)) {
-      document_load_state_ = LOAD_STATE_LOADING;
-      DocumentLoadFailed();
-    }
-  } else if (result != PP_ERROR_ABORTED) {  // Can happen in tests.
-    NOTREACHED();
+  if (result != PP_OK || !engine_->HandleDocumentLoad(embed_loader_))
     DocumentLoadFailed();
-  }
 }
 
 void OutOfProcessInstance::DidOpenPreview(int32_t result) {
@@ -1450,6 +1443,7 @@ void OutOfProcessInstance::LoadUrlInternal(
   pp::URLRequestInfo request(this);
   request.SetURL(url);
   request.SetMethod("GET");
+  request.SetFollowRedirects(false);
 
   *loader = CreateURLLoaderInternal();
   pp::CompletionCallback callback = loader_factory_.NewCallback(method);