Do not trigger CrossSiteResourceHandler for streams or user certs.

content/browser/loader/buffered_resource_handler.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 "content/browser/loader/buffered_resource_handler.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 289 matching lines @@
 }
 
 bool BufferedResourceHandler::SelectNextHandler(bool* defer) {
   DCHECK(!response_->head.mime_type.empty());
 
   ResourceRequestInfoImpl* info = GetRequestInfo();
   const std::string& mime_type = response_->head.mime_type;
 
   if (net::IsSupportedCertificateMimeType(mime_type)) {
     // Install certificate file.
+    info->set_is_download(true);
     scoped_ptr<ResourceHandler> handler(
         new CertificateResourceHandler(request()));
     return UseAlternateNextHandler(handler.Pass());
   }
 
   if (!info->allow_download())
     return true;
 
   bool must_download = MustDownload();
   if (!must_download) {
@@ skipping 45 matching lines @@
     //               of check is scattered throughout our codebase.
     request()->CancelWithError(net::ERR_FILE_NOT_FOUND);
     return false;
   }
 
   int request_id = GetRequestID();
 
   // Inform the original ResourceHandler that this will be handled entirely by
   // the new ResourceHandler.
   // TODO(darin): We should probably check the return values of these.
-  // TODO(davidben): These DCHECKs do actually trigger.

[davidben, 2014/02/12 19:58:56]

(Removed this comment and replaced it with the other since I added it in
response to hitting the x-x509-user-cert case. Forgot to look into it until
now.)

   bool defer_ignored = false;
   next_handler_->OnResponseStarted(request_id, response_.get(), &defer_ignored);
+  // Although deferring OnResponseStarted is legal, the only downstream handler
+  // which does so is CrossSiteResourceHandler. Cross-site transitions should
+  // not trigger when switching handlers.
   DCHECK(!defer_ignored);
   net::URLRequestStatus status(net::URLRequestStatus::CANCELED,
                                net::ERR_ABORTED);
   next_handler_->OnResponseCompleted(request_id, status, std::string(),
                                      &defer_ignored);
   DCHECK(!defer_ignored);
 
   // This is handled entirely within the new ResourceHandler, so just reset the
   // original ResourceHandler.
   next_handler_ = new_handler.Pass();
@@ skipping 84 matching lines @@
     const std::vector<WebPluginInfo>& plugins) {
   bool defer = false;
   if (!ProcessResponse(&defer)) {
     controller()->Cancel();
   } else if (!defer) {
     controller()->Resume();
   }
 }
 
 }  // namespace content