ipc: Create AttachmentBrokerPrivileged and AttachmentBrokerUnprivileged.

ipc/attachment_broker_privileged_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_ATTACHMENT_BROKER_PRIVILEGED_WIN_H_
 #define IPC_ATTACHMENT_BROKER_PRIVILEGED_WIN_H_
 
-#include <vector>
-
-#include "ipc/attachment_broker.h"
+#include "ipc/attachment_broker_privileged.h"
 #include "ipc/handle_attachment_win.h"
 #include "ipc/ipc_export.h"
 
 namespace IPC {
 
-class Channel;
-
-// This class is an implementation of AttachmentBroker for a privileged process
-// on the Windows platform. When unprivileged processes want to send
-// attachments, the attachments get routed through the privileged process, and
-// more specifically, an instance of this class.
-class IPC_EXPORT AttachmentBrokerPrivilegedWin : public AttachmentBroker {
+// This class is a concrete subclass of AttachmentBrokerPrivileged for the
+// Windows platform.
+class IPC_EXPORT AttachmentBrokerPrivilegedWin
+    : public AttachmentBrokerPrivileged {
  public:
   AttachmentBrokerPrivilegedWin();
   ~AttachmentBrokerPrivilegedWin() override;
 
   // IPC::AttachmentBroker overrides.
   bool SendAttachmentToProcess(const BrokerableAttachment* attachment,
                                base::ProcessId destination_process) override;
 
   // IPC::Listener overrides.
   bool OnMessageReceived(const Message& message) override;
 
-  // Each unprivileged process should have one IPC channel on which it
-  // communicates attachment information with this privileged process. These
-  // channels must be registered and deregistered with the Attachment Broker as
-  // they are created and destroyed.
-  void RegisterCommunicationChannel(Channel* channel);
-  void DeregisterCommunicationChannel(Channel* channel);
-
  private:
   using HandleWireFormat = internal::HandleAttachmentWin::WireFormat;
   // IPC message handlers.
   void OnDuplicateWinHandle(const IPC::Message& message);
 
   // Duplicates |wire_Format| from |source_process| into its destination
   // process.
   HandleWireFormat DuplicateWinHandle(const HandleWireFormat& wire_format,
                                       base::ProcessId source_process);
 
   // If the HANDLE's destination is this process, queue it and notify the
   // observers. Otherwise, send it in an IPC to its destination.
   void RouteDuplicatedHandle(const HandleWireFormat& wire_format);
 
-  std::vector<Channel*> channels_;
   DISALLOW_COPY_AND_ASSIGN(AttachmentBrokerPrivilegedWin);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_ATTACHMENT_BROKER_PRIVILEGED_WIN_H_