Remove handler from MessagePumpForIO::IOContext.

net/base/file_stream_context_win.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 <windows.h>
 #include <utility>
 
 #include "base/files/file_path.h"
@@ skipping 26 matching lines @@
 }  // namespace
 
 FileStream::Context::Context(const scoped_refptr<base::TaskRunner>& task_runner)
     : async_in_progress_(false),
       orphaned_(false),
       task_runner_(task_runner),
       io_context_(),
       async_read_initiated_(false),
       async_read_completed_(false),
       io_complete_for_read_received_(false),
-      result_(0) {
-  io_context_.handler = this;
-  memset(&io_context_.overlapped, 0, sizeof(io_context_.overlapped));
-}
+      result_(0) {}
 
 FileStream::Context::Context(base::File file,
                              const scoped_refptr<base::TaskRunner>& task_runner)
     : file_(std::move(file)),
       async_in_progress_(false),
       orphaned_(false),
       task_runner_(task_runner),
       io_context_(),
       async_read_initiated_(false),
       async_read_completed_(false),
       io_complete_for_read_received_(false),
       result_(0) {
-  io_context_.handler = this;
-  memset(&io_context_.overlapped, 0, sizeof(io_context_.overlapped));
   if (file_.IsValid()) {
     DCHECK(file_.async());
     OnFileOpened();
   }
 }
 
 FileStream::Context::~Context() {
 }
 
 int FileStream::Context::Read(IOBuffer* buf,
@@ skipping 161 matching lines @@
 
   IOResult error = IOResult::FromOSError(os_error);
   if (error.os_error == ERROR_IO_PENDING) {
     InvokeUserCallback();
   } else {
     OnIOCompleted(&io_context_, 0, error.os_error);
   }
 }
 
 }  // namespace net