Remove unused code and ipc_handle_win.(h|cc).

ipc/ipc_handle_win.h

Index: ipc/ipc_handle_win.h
diff --git a/ipc/ipc_handle_win.h b/ipc/ipc_handle_win.h
deleted file mode 100644
index 47779bdefcdc53b462ea956e3c305651ef62d717..0000000000000000000000000000000000000000
--- a/ipc/ipc_handle_win.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2015 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 IPC_HANDLE_WIN_H_
-#define IPC_HANDLE_WIN_H_
-
-#include <windows.h>
-
-namespace IPC {
-
-// This class is a wrapper around HANDLE. It can be passed between Chrome
-// processes via Chrome IPC.
-struct HandleForTransit {
-  HANDLE handle;
-};
-
-HandleForTransit CreateHandleForTransit(HANDLE handle);
-
-}  // namespace IPC
-
-#endif  // IPC_HANDLE_WIN_H_