google_apis: Stop accessing URLFetcher from ResponseWriter

google_apis/drive/base_requests.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.
 //
 // This file provides base classes used to issue HTTP requests for Google
 // APIs.
 
 #ifndef GOOGLE_APIS_DRIVE_BASE_REQUESTS_H_
 #define GOOGLE_APIS_DRIVE_BASE_REQUESTS_H_
 
@@ skipping 76 matching lines @@
   virtual void Cancel() = 0;
 };
 
 //=========================== ResponseWriter ==================================
 
 // Saves the response for the request to a file or string.
 class ResponseWriter : public net::URLFetcherResponseWriter {
  public:
   // If file_path is not empty, the response will be saved with file_writer_,
   // otherwise it will be saved to data_.
-  ResponseWriter(net::URLFetcher* url_fetcher,
-                 base::SequencedTaskRunner* file_task_runner,
+  ResponseWriter(base::SequencedTaskRunner* file_task_runner,
                  const base::FilePath& file_path,
                  const GetContentCallback& get_content_callback);
   virtual ~ResponseWriter();
 
   const std::string& data() const { return data_; }
 
   // Disowns the output file.
   void DisownFile();
 
   // URLFetcherResponseWriter overrides:
   virtual int Initialize(const net::CompletionCallback& callback) OVERRIDE;
   virtual int Write(net::IOBuffer* buffer,
                     int num_bytes,
                     const net::CompletionCallback& callback) OVERRIDE;
   virtual int Finish(const net::CompletionCallback& callback) OVERRIDE;
 
  private:
-  net::URLFetcher* url_fetcher_;
+  void DidWrite(scoped_refptr<net::IOBuffer> buffer,
+                const net::CompletionCallback& callback,
+                int result);
+
   const GetContentCallback get_content_callback_;
   std::string data_;
   scoped_ptr<net::URLFetcherFileWriter> file_writer_;
+  base::WeakPtrFactory<ResponseWriter> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResponseWriter);
 };
 
 //============================ UrlFetchRequestBase ===========================
 
 // Base class for requests that are fetching URLs.
 class UrlFetchRequestBase : public AuthenticatedRequestInterface,
                             public net::URLFetcherDelegate {
  public:
@@ skipping 397 matching lines @@
   const ProgressCallback progress_callback_;
   const GURL download_url_;
   const base::FilePath output_file_path_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileRequestBase);
 };
 
 }  // namespace google_apis
 
 #endif  // GOOGLE_APIS_DRIVE_BASE_REQUESTS_H_