net: Allow URLFetcher users to inject custom URLFetcherResponseWriter

net/url_request/url_fetcher.h

 // 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.
 
 #ifndef NET_URL_REQUEST_URL_FETCHER_H_
 #define NET_URL_REQUEST_URL_FETCHER_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/supports_user_data.h"
 #include "base/task_runner.h"
 #include "net/base/net_export.h"
 
 class GURL;
 
 namespace base {
 class FilePath;
 class MessageLoopProxy;
 class TimeDelta;
 }
 
 namespace net {
 class HostPortPair;
 class HttpRequestHeaders;
 class HttpResponseHeaders;
 class URLFetcherDelegate;
+class URLFetcherResponseWriter;
 class URLRequestContextGetter;
 class URLRequestStatus;
 typedef std::vector<std::string> ResponseCookies;
 
 // To use this class, create an instance with the desired URL and a pointer to
 // the object to be notified when the URL has been loaded:
 //   URLFetcher* fetcher = URLFetcher::Create("http://www.google.com",
 //                                            URLFetcher::GET, this);
 //
 // You must also set a request context getter:
@@ skipping 192 matching lines @@
       scoped_refptr<base::TaskRunner> file_task_runner) = 0;
 
   // By default, the response is saved in a string. Call this method to save the
   // response to a temporary file instead. Must be called before Start().
   // |file_task_runner| will be used for all file operations.
   // The created file is removed when the URLFetcher is deleted unless you
   // take ownership by calling GetResponseAsFilePath().
   virtual void SaveResponseToTemporaryFile(
       scoped_refptr<base::TaskRunner> file_task_runner) = 0;
 
+  // By default, the response is saved in a string. Call this method to use the
+  // specified writer to save the response. Must be called before Start().
+  virtual void SaveResponseWithWriter(
+      scoped_ptr<URLFetcherResponseWriter> response_writer) = 0;

[wtc, 2013/10/14 19:57:23]

Why don't you remove the SaveResponseToFileAtPath and
SaveResponseToTemporaryFile methods? Are you planning to remove them later?

[hashimoto, 2013/10/15 01:00:35]

I thought it might be OK to leave SaveResponseToFileAtPath,
SaveResponseToTemporaryFile and GetResponseAsFilePath unremoved because these
methods are quite simple now.
But if we are to remove these methods, we can do it later, after converting all
user code (Google Drive, imageburner, component_updater and extension_download)
to use SaveResponseWithWriter.

+
   // Retrieve the response headers from the request.  Must only be called after
   // the OnURLFetchComplete callback has run.
   virtual HttpResponseHeaders* GetResponseHeaders() const = 0;
 
   // Retrieve the remote socket address from the request.  Must only
   // be called after the OnURLFetchComplete callback has run and if
   // the request has not failed.
   virtual HostPortPair GetSocketAddress() const = 0;
 
   // Returns true if the request was delivered through a proxy.  Must only
@@ skipping 34 matching lines @@
   // be removed once the URLFetcher is destroyed.  User should not take
   // ownership more than once, or call this method after taking ownership.
   virtual bool GetResponseAsFilePath(
       bool take_ownership,
       base::FilePath* out_response_path) const = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_FETCHER_H_