net: Make UploadDataStream::Init() asynchronous.

net/base/upload_file_element_reader.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_BASE_UPLOAD_FILE_ELEMENT_READER_H_
 #define NET_BASE_UPLOAD_FILE_ELEMENT_READER_H_
 
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
 #include "base/time.h"
 #include "net/base/upload_element_reader.h"
 
 namespace net {
 
 class FileStream;
 
 // An UploadElementReader implementation for file.
 class NET_EXPORT_PRIVATE UploadFileElementReader : public UploadElementReader {
  public:
   UploadFileElementReader(const FilePath& path,
                           uint64 range_offset,
                           uint64 range_length,
                           const base::Time& expected_modification_time);
   virtual ~UploadFileElementReader();
 
   // UploadElementReader overrides:
+  virtual int Init(const CompletionCallback& callback) OVERRIDE;
   virtual int InitSync() OVERRIDE;
   virtual uint64 GetContentLength() const OVERRIDE;
   virtual uint64 BytesRemaining() const OVERRIDE;
   virtual int ReadSync(char* buf, int buf_length) OVERRIDE;
 
  private:
+  // This method is used to implement Init().
+  void OnInitCompleted(scoped_ptr<FileStream>* file_stream,
+                       uint64* content_length,
+                       int* result,
+                       const CompletionCallback& callback);
+
   // Sets an value to override the result for GetContentLength().
   // Used for tests.
   struct NET_EXPORT_PRIVATE ScopedOverridingContentLengthForTests {
     ScopedOverridingContentLengthForTests(uint64 value);
     ~ScopedOverridingContentLengthForTests();
   };
 
   FilePath path_;
   uint64 range_offset_;
   uint64 range_length_;
   base::Time expected_modification_time_;
   scoped_ptr<FileStream> file_stream_;
   uint64 content_length_;
   uint64 bytes_remaining_;
+  base::WeakPtrFactory<UploadFileElementReader> weak_ptr_factory_;
 
   FRIEND_TEST_ALL_PREFIXES(UploadDataStreamTest, FileSmallerThanLength);
   FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionTest,
                            UploadFileSmallerThanLength);
   FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionSpdy2Test,
                            UploadFileSmallerThanLength);
   FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionSpdy3Test,
                            UploadFileSmallerThanLength);
 
   DISALLOW_COPY_AND_ASSIGN(UploadFileElementReader);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_UPLOAD_FILE_ELEMENT_READER_H_