Consider the Access-Control-Allow-Origin header for Background Fetch

content/browser/background_fetch/background_fetch_request_info.cc

 // Copyright 2017 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/background_fetch/background_fetch_request_info.h"
 
 #include <string>
 
+#include "base/strings/string_util.h"
 #include "content/public/browser/download_item.h"
 #include "net/http/http_response_headers.h"
 
 namespace content {
 
 BackgroundFetchRequestInfo::BackgroundFetchRequestInfo(
     int request_index,
     const ServiceWorkerFetchRequest& fetch_request)
     : request_index_(request_index), fetch_request_(fetch_request) {}
 
@@ skipping 12 matching lines @@
   if (download_item->GetResponseHeaders()) {
     const auto& headers = download_item->GetResponseHeaders();
 
     response_code_ = headers->response_code();
     response_text_ = headers->GetStatusText();
 
     size_t iter = 0;
     std::string name, value;
 
     while (headers->EnumerateHeaderLines(&iter, &name, &value))
-      response_headers_[name] = value;
+      response_headers_[base::ToLowerASCII(name)] = value;
   }
 
   download_state_populated_ = true;
 }
 
 void BackgroundFetchRequestInfo::PopulateResponseFromDownloadItem(
     DownloadItem* download_item) {
   DCHECK(!response_data_populated_);
 
   url_chain_ = download_item->GetUrlChain();
@@ skipping 34 matching lines @@
   DCHECK(response_data_populated_);
   return file_size_;
 }
 
 const base::Time& BackgroundFetchRequestInfo::GetResponseTime() const {
   DCHECK(response_data_populated_);
   return response_time_;
 }
 
 }  // namespace content