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

content/browser/background_fetch/background_fetch_request_info.h

 // 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.
 
 #ifndef CONTENT_BROWSER_BACKGROUND_FETCH_REQUEST_INFO_H_
 #define CONTENT_BROWSER_BACKGROUND_FETCH_REQUEST_INFO_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 42 matching lines @@
 
   // Returns the absolute path to the file in which the response is stored.
   const base::FilePath& GetFilePath() const;
 
   // Returns the size of the file containing the response, in bytes.
   int64_t GetFileSize() const;
 
   // Returns the time at which the response was completed.
   const base::Time& GetResponseTime() const;
 
+  // Returns the mime type describing the response, as indicated by the server.
+  const std::string& GetResponseType() const;
+
  private:
   friend class base::RefCountedThreadSafe<BackgroundFetchRequestInfo>;
 
   ~BackgroundFetchRequestInfo();
 
   // ---- Data associated with the request -------------------------------------
 
   int request_index_ = kInvalidBackgroundFetchRequestIndex;
   ServiceWorkerFetchRequest fetch_request_;
 
   // ---- Data associated with the in-progress download ------------------------
 
   // Indicates whether download progress data has been populated.
   bool download_state_populated_ = false;
 
   std::string download_guid_;
   DownloadItem::DownloadState download_state_ = DownloadItem::IN_PROGRESS;
 
   // ---- Data associated with the response ------------------------------------
 
   // Indicates whether response data has been populated.
   bool response_data_populated_ = false;
 
   std::vector<GURL> url_chain_;
   base::FilePath file_path_;
   int64_t file_size_ = 0;
   base::Time response_time_;
+  std::string response_type_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundFetchRequestInfo);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BACKGROUND_FETCH_REQUEST_INFO_H_