Make attachment broker a subclass of IPC::Listener.

ipc/attachment_broker_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_WIN_H_
 #define IPC_ATTACHMENT_BROKER_WIN_H_
 
+#include <vector>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/ref_counted.h"
 #include "ipc/attachment_broker.h"
+#include "ipc/handle_attachment_win.h"
 #include "ipc/ipc_export.h"
 
 namespace IPC {
 
 class Sender;
 
 // This class is an implementation of AttachmentBroker for the Windows platform.
 class IPC_EXPORT AttachmentBrokerWin : public IPC::AttachmentBroker {
  public:
   AttachmentBrokerWin();
   ~AttachmentBrokerWin() override;
 
   // In a non-broker process, the single instance of this class listens for
   // an IPC from the broker process indicating that a new attachment has been
   // duplicated.
   void OnReceiveDuplicatedHandle(HANDLE, BrokerableAttachment::AttachmentId id);
 
   // IPC::AttachmentBroker overrides.
   bool SendAttachmentToProcess(const BrokerableAttachment* attachment,
                                base::ProcessId destination_process) override;
   bool GetAttachmentWithId(BrokerableAttachment::AttachmentId id,
                            BrokerableAttachment* attachment) override;
 
+  // IPC::Listener overrides.
+  bool OnMessageReceived(const Message& message) override;
+
   // |sender_| is used to send Messages to the broker. |sender_| must live at
   // least as long as this instance.
   void set_sender(IPC::Sender* sender) { sender_ = sender; }
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(AttachmentBrokerWinTest, ReceiveValidMessage);
+  FRIEND_TEST_ALL_PREFIXES(AttachmentBrokerWinTest, ReceiveInvalidMessage);
+
+  // IPC message handlers.
+  void OnWinHandleHasBeenDuplicated(
+      const IPC::internal::HandleAttachmentWin::WireFormat& wire_format);
+
+  // A vector of BrokerableAttachments that have been received, but not yet
+  // consumed.
+  // A std::vector is used instead of a std::map because this container is
+  // expected to have few elements, for which a std::vector is expected to have
+  // better performance.
+  std::vector<scoped_refptr<BrokerableAttachment>> attachments_;
+
   // |sender_| is used to send Messages to the broker. |sender_| must live at
   // least as long as this instance.
   IPC::Sender* sender_;
   DISALLOW_COPY_AND_ASSIGN(AttachmentBrokerWin);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_ATTACHMENT_BROKER_WIN_H_