Fix various issues in RedirectToFileResourceHandler.

content/browser/loader/async_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/async_resource_handler.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 179 matching lines @@
 
   if (info->GetResourceType() == ResourceType::MAIN_FRAME && host_zoom_map) {
     const GURL& request_url = request()->url();
     info->filter()->Send(new ViewMsg_SetZoomLevelForLoadingURL(
         info->GetRouteID(),
         request_url, host_zoom_map->GetZoomLevelForHostAndScheme(
             request_url.scheme(),
             net::GetHostOrSpecFromURL(request_url))));
   }
 
+  // If the parent handler downloaded the resource to a file, grant the child
+  // read permissions on it.
+  if (!response->head.download_file_path.empty()) {
+    rdh_->RegisterDownloadedTempFile(
+        info->GetChildID(), info->GetRequestID(),
+        response->head.download_file_path);
+  }

[mmenke, 2014/01/16 16:43:26]

Sure you don't want to keep this in the RedirectToFileResourceHandler?  I'm a
little concerned about changes/fixes here not making it into the
SyncResourceHandler as well.

[davidben, 2014/01/29 21:41:50]

Well, keeping it in RedirectToFileResourceHandler keeps the RTFRH -> RDH
dependency, which is what made it difficult to unit test in the first place. The
previous version put it in the CreateTemporary implementation, but it seemed
doing it right before sending the file path to the renderer was more
appropriate. (Also this means the mocked out function doesn't need to tie back
to the RDH and care about that thing's lifetime.)

I've added a comment to the two copies. We may also be able to just remove
SyncResourceHandler's download_to_file support altogether. I couldn't find code
in Blink that cared about it. And I think the loadSynchronously codepaths never
read from the blob handle renderer-side, so if it did happen, it wouldn't work.
Added a TODO about getting rid of it.

+
   response->head.request_start = request()->creation_time();
   response->head.response_start = TimeTicks::Now();
   info->filter()->Send(new ResourceMsg_ReceivedResponse(request_id,
                                                         response->head));
   sent_received_response_msg_ = true;
 
   if (request()->response_info().metadata.get()) {
     std::vector<char> copy(request()->response_info().metadata->data(),
                            request()->response_info().metadata->data() +
                                request()->response_info().metadata->size());
@@ skipping 172 matching lines @@
     request()->LogUnblocked();
     controller()->Resume();
   }
 }
 
 void AsyncResourceHandler::OnDefer() {
   request()->LogBlockedBy("AsyncResourceHandler");
 }
 
 }  // namespace content