Cleanup remaining class/struct fwd declarations

ipc/handle_win.h

 // 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>
 
 #include <string>
 
 #include "ipc/ipc_export.h"
 #include "ipc/ipc_param_traits.h"
 
 namespace base {
 class Pickle;
 class PickleIterator;
 }  // namespace base
 
 namespace IPC {
 
-class Message;
-
 // HandleWin is a wrapper around a Windows HANDLE that can be transported
 // across Chrome IPC channels that support attachment brokering. The HANDLE will
 // be duplicated into the destination process.
 //
 // The ownership semantics for the underlying |handle_| are complex. See
 // ipc/mach_port_mac.h (the OSX analog of this class) for an extensive
 // discussion.
 class IPC_EXPORT HandleWin {
  public:
   enum Permissions {
@@ skipping 26 matching lines @@
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,
                    param_type* p);
   static void Log(const param_type& p, std::string* l);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_HANDLE_WIN_H_