Make IPC channels track their peer process ID

ipc/ipc_channel_win.h

 // Copyright (c) 2012 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_IPC_CHANNEL_WIN_H_
 #define IPC_IPC_CHANNEL_WIN_H_
 #pragma once
 
 #include "ipc/ipc_channel.h"
 
@@ skipping 15 matching lines @@
                              public MessageLoopForIO::IOHandler {
  public:
   // Mirror methods of Channel, see ipc_channel.h for description.
   ChannelImpl(const IPC::ChannelHandle &channel_handle, Mode mode,
               Listener* listener);
   ~ChannelImpl();
   bool Connect();
   void Close();
   bool Send(Message* message);
   static bool IsNamedServerInitialized(const std::string& channel_id);
+  base::ProcessId peer_pid() const { return peer_pid_; }
 
  private:
   // ChannelReader implementation.
   virtual ReadState ReadData(char* buffer,
                              int buffer_len,
                              int* bytes_read) OVERRIDE;
   virtual bool WillDispatchInputMessage(Message* msg) OVERRIDE;
   bool DidEmptyInputBuffers() OVERRIDE;
   virtual void HandleHelloMessage(const Message& msg) OVERRIDE;
 
@@ skipping 14 matching lines @@
     ~State();
     MessageLoopForIO::IOContext context;
     bool is_pending;
   };
 
   State input_state_;
   State output_state_;
 
   HANDLE pipe_;
 
+  base::ProcessId peer_pid_;
+
   // Messages to be sent are queued here.
   std::queue<Message*> output_queue_;
 
   // In server-mode, we have to wait for the client to connect before we
   // can begin reading.  We make use of the input_state_ when performing
   // the connect operation in overlapped mode.
   bool waiting_connect_;
 
   // This flag is set when processing incoming messages.  It is used to
   // avoid recursing through ProcessIncomingMessages, which could cause
@@ skipping 13 matching lines @@
   base::WeakPtrFactory<ChannelImpl> weak_factory_;
 
   scoped_ptr<base::NonThreadSafe> thread_check_;
 
   DISALLOW_COPY_AND_ASSIGN(ChannelImpl);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_CHANNEL_WIN_H_