Remove handler from MessagePumpForIO::IOContext.

net/disk_cache/blockfile/file_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/disk_cache/blockfile/file.h"
 
 #include <limits.h>
 #include <utility>
 
 #include "base/files/file_path.h"
@@ skipping 45 matching lines @@
 
   if (data->callback_)
     data->callback_->OnFileIOComplete(static_cast<int>(actual_bytes));
 
   delete data;
 }
 
 MyOverlapped::MyOverlapped(disk_cache::File* file, size_t offset,
                            disk_cache::FileIOCallback* callback) {
   memset(this, 0, sizeof(*this));
-  context_.handler = g_completion_handler.Pointer();
   context_.overlapped.Offset = static_cast<DWORD>(offset);
   file_ = file;
   callback_ = callback;
 }
 
 }  // namespace
 
 namespace disk_cache {
 
 File::File(base::File file)
@@ skipping 172 matching lines @@
     base::MessageLoopForIO::IOHandler* handler = g_completion_handler.Pointer();
     base::MessageLoopForIO::current()->WaitForIOCompletion(100, handler);
   }
 }
 
 // Static.
 void File::DropPendingIO() {
 }
 
 }  // namespace disk_cache