Add SHARED_DELETE flag to FileStream.

net/base/file_stream_context.cc

 // 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.
 
 #include "net/base/file_stream_context.h"
 
 #include "base/location.h"
 #include "base/message_loop_proxy.h"
 #include "base/task_runner_util.h"
 #include "base/threading/thread_restrictions.h"
@@ skipping 133 matching lines @@
 }
 
 void FileStream::Context::BeginOpenEvent(const FilePath& path) {
   std::string file_name = path.AsUTF8Unsafe();
   bound_net_log_.BeginEvent(NetLog::TYPE_FILE_STREAM_OPEN,
                             NetLog::StringCallback("file_name", &file_name));
 }
 
 FileStream::Context::OpenResult FileStream::Context::OpenFileImpl(
     const FilePath& path, int open_flags) {
+  // FileStream::Context actually closes the file asynchronously, independently
+  // from FileStream's destructor. It can cause problems for users wanting to
+  // delete the file right after FileStream deletion. Thus we are always
+  // adding SHARE_DELETE flag to accommodate such use case.

[wtc, 2012/12/12 20:05:17]

I suggest clarifying this comment as follows.

1. On line 154, change
    FileStream::Context
to
    FileStream::Context::CloseAndDelete()

Does FileStream::Context::CloseAndDelete() delete the file
or delete the FileStream::Context object? I think it's the
latter, so the "CloseAndDelete" function name is a little
confusing.

2. Point out that on Windows, the FILE_SHARE_DELETE flag
allows a DeleteFile() call to succeed when there is still
an open handle to the file. This matches the Unix behavior.

+  open_flags |= base::PLATFORM_FILE_SHARE_DELETE;
   OpenResult result;
   result.error_code = OK;
   result.file = base::CreatePlatformFile(path, open_flags, NULL, NULL);
   if (result.file == base::kInvalidPlatformFileValue)
     result.error_code = GetLastErrno();
 
   return result;
 }
 
 int FileStream::Context::ProcessOpenError(int error_code) {
@@ skipping 58 matching lines @@
   // operation is in progress.
   async_in_progress_ = false;
   if (orphaned_)
     CloseAndDelete();
   else
     callback.Run(result);
 }
 
 }  // namespace net