Set the Content-Type and Content-Length headers for BG Fetch

content/browser/background_fetch/background_fetch_request_info.cc

Index: content/browser/background_fetch/background_fetch_request_info.cc
diff --git a/content/browser/background_fetch/background_fetch_request_info.cc b/content/browser/background_fetch/background_fetch_request_info.cc
index 0047606157d8318f4f9ca80ec5645a235d9576a3..0beb3c9fac044b63215ffb973912782b9bbe335a 100644
--- a/content/browser/background_fetch/background_fetch_request_info.cc
+++ b/content/browser/background_fetch/background_fetch_request_info.cc
@@ -36,6 +36,7 @@ void BackgroundFetchRequestInfo::PopulateResponseFromDownloadItem(
   file_path_ = download_item->GetTargetFilePath();
   file_size_ = download_item->GetReceivedBytes();
   response_time_ = download_item->GetEndTime();
+  response_type_ = download_item->GetMimeType();
 
   response_data_populated_ = true;
 }
@@ -60,4 +61,9 @@ const base::Time& BackgroundFetchRequestInfo::GetResponseTime() const {
   return response_time_;
 }
 
+const std::string& BackgroundFetchRequestInfo::GetResponseType() const {
+  DCHECK(response_data_populated_);
+  return response_type_;
+}
+
 }  // namespace content