Remove IPC::BrokerableAttachment.

ipc/brokerable_attachment.h

Index: ipc/brokerable_attachment.h
diff --git a/ipc/brokerable_attachment.h b/ipc/brokerable_attachment.h
deleted file mode 100644
index a926d5bfe67089b3d98f262e44705283f3c71c01..0000000000000000000000000000000000000000
--- a/ipc/brokerable_attachment.h
+++ /dev/null
@@ -1,54 +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_BROKERABLE_ATTACHMENT_H_
-#define IPC_BROKERABLE_ATTACHMENT_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <algorithm>
-
-#include "base/macros.h"
-#include "build/build_config.h"
-#include "ipc/ipc_export.h"
-#include "ipc/ipc_message_attachment.h"
-
-namespace IPC {
-
-// This subclass of MessageAttachment requires an AttachmentBroker to be
-// attached to a Chrome IPC message.
-class IPC_EXPORT BrokerableAttachment : public MessageAttachment {
- public:
-  enum BrokerableType {
-    PLACEHOLDER,
-    WIN_HANDLE,
-    MACH_PORT,
-  };
-
-  // Whether the attachment still needs information from the broker before it
-  // can be used.
-  bool NeedsBrokering() const;
-
-  // Returns TYPE_BROKERABLE_ATTACHMENT
-  Type GetType() const override;
-
-  virtual BrokerableType GetBrokerableType() const = 0;
-
-// MessageAttachment override.
-#if defined(OS_POSIX)
-  base::PlatformFile TakePlatformFile() override;
-#endif  // OS_POSIX
-
- protected:
-  BrokerableAttachment();
-  ~BrokerableAttachment() override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(BrokerableAttachment);
-};
-
-}  // namespace IPC
-
-#endif  // IPC_BROKERABLE_ATTACHMENT_H_