Make IPC::Channel polymorphic

ipc/ipc_channel_posix.h

Index: ipc/ipc_channel_posix.h
diff --git a/ipc/ipc_channel_posix.h b/ipc/ipc_channel_posix.h
index 1e587c13eb0d02e8737db4d6c088659356656e3e..ae2de72f7fe3fa582a90ff379efb4b043b68f1ad 100644
--- a/ipc/ipc_channel_posix.h
+++ b/ipc/ipc_channel_posix.h
@@ -49,24 +49,29 @@
 
 namespace IPC {
 
-class Channel::ChannelImpl : public internal::ChannelReader,
-                             public base::MessageLoopForIO::Watcher {
+class ChannelPosix : public Channel,
+                     public internal::ChannelReader,
+                     public base::MessageLoopForIO::Watcher {
  public:
   // Mirror methods of Channel, see ipc_channel.h for description.
-  ChannelImpl(const IPC::ChannelHandle& channel_handle, Mode mode,
-              Listener* listener);
-  virtual ~ChannelImpl();
-  bool Connect();
-  void Close();
-  bool Send(Message* message);
-  int GetClientFileDescriptor();
-  int TakeClientFileDescriptor();
+  ChannelPosix(const IPC::ChannelHandle& channel_handle, Mode mode,
+               Listener* listener);
+  virtual ~ChannelPosix();
+
+  // Channel implementation
+  virtual bool Connect() OVERRIDE;
+  virtual void Close() OVERRIDE;
+  virtual bool Send(Message* message) OVERRIDE;
+  virtual base::ProcessId GetPeerPID() const OVERRIDE;
+  virtual int GetClientFileDescriptor() const OVERRIDE;
+  virtual int TakeClientFileDescriptor() OVERRIDE;
+  virtual bool AcceptsConnections() const OVERRIDE;
+  virtual bool HasAcceptedConnection() const OVERRIDE;
+  virtual bool GetPeerEuid(uid_t* peer_euid) const OVERRIDE;
+  virtual void ResetToAcceptingConnectionState() OVERRIDE;
+
   void CloseClientFileDescriptor();
-  bool AcceptsConnections() const;
-  bool HasAcceptedConnection() const;
-  bool GetPeerEuid(uid_t* peer_euid) const;
-  void ResetToAcceptingConnectionState();
-  base::ProcessId peer_pid() const { return peer_pid_; }
+
   static bool IsNamedServerInitialized(const std::string& channel_id);
 #if defined(OS_LINUX)
   static void SetGlobalPid(int pid);
@@ -144,7 +149,7 @@ class Channel::ChannelImpl : public internal::ChannelReader,
   // For a server, the client end of our socketpair() -- the other end of our
   // pipe_ that is passed to the client.
   int client_pipe_;
-  base::Lock client_pipe_lock_;  // Lock that protects |client_pipe_|.
+  mutable base::Lock client_pipe_lock_;  // Lock that protects |client_pipe_|.
 
 #if defined(IPC_USES_READWRITE)
   // Linux/BSD use a dedicated socketpair() for passing file descriptors.
@@ -202,7 +207,7 @@ class Channel::ChannelImpl : public internal::ChannelReader,
   static int global_pid_;
 #endif  // OS_LINUX
 
-  DISALLOW_IMPLICIT_CONSTRUCTORS(ChannelImpl);
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ChannelPosix);
 };
 
 }  // namespace IPC