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

content/browser/background_fetch/background_fetch_request_info.h

Index: content/browser/background_fetch/background_fetch_request_info.h
diff --git a/content/browser/background_fetch/background_fetch_request_info.h b/content/browser/background_fetch/background_fetch_request_info.h
index d5939be993135167187897d2287e3d21d0a5a9b4..6c61101231335e7cb2f6fe740d76b9ea1e6031ba 100644
--- a/content/browser/background_fetch/background_fetch_request_info.h
+++ b/content/browser/background_fetch/background_fetch_request_info.h
@@ -60,6 +60,9 @@ class CONTENT_EXPORT BackgroundFetchRequestInfo
   // 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>;
 
@@ -87,6 +90,7 @@ class CONTENT_EXPORT BackgroundFetchRequestInfo
   base::FilePath file_path_;
   int64_t file_size_ = 0;
   base::Time response_time_;
+  std::string response_type_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundFetchRequestInfo);
 };