Alter the design of the bootstrap sandbox to only take over the bootstrap port of children when nec…

sandbox/mac/mach_message_server.h

 // Copyright 2014 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 SANDBOX_MAC_MACH_MESSAGE_SERVER_H_
 #define SANDBOX_MAC_MACH_MESSAGE_SERVER_H_
 
 #include <dispatch/dispatch.h>
 #include <mach/mach.h>
 
@@ skipping 15 matching lines @@
  protected:
   virtual ~MessageDemuxer() {}
 };
 
 // A Mach message server that operates a receive port. Messages are received
 // and then passed to the MessageDemuxer for handling. The Demuxer
 // can use the server class to send a reply, forward the message to a
 // different port, or reply to the message with a MIG error.
 class MachMessageServer {
  public:
-  MachMessageServer(MessageDemuxer* demuxer, mach_msg_size_t buffer_size);
+  // Creates a new Mach message server that will send messages to |demuxer|
+  // for handling. If the |server_receive_right| is non-NULL, this class will
+  // take ownership of the port and it will be used to receive messages.
+  // Otherwise the server will create a new receive right.
+  // The maximum size of messages is specified by |buffer_size|.
+  MachMessageServer(MessageDemuxer* demuxer,
+                    mach_port_t server_receive_right,
+                    mach_msg_size_t buffer_size);
   ~MachMessageServer();
 
   // Initializes the class and starts running the message server. If this
   // returns false, no other methods may be called on this class.
   bool Initialize();
 
   // Given a received request message, returns the PID of the sending process.
   pid_t GetMessageSenderPID(mach_msg_header_t* request);
 
   // Sends a reply message. Returns true if the message was sent successfully.
@@ skipping 32 matching lines @@
   base::mac::ScopedMachVM request_buffer_;
   base::mac::ScopedMachVM reply_buffer_;
 
   // Whether or not ForwardMessage() was called during ReceiveMessage().
   bool did_forward_message_;
 };
 
 }  // namespace sandbox
 
 #endif  // SANDBOX_MAC_MACH_MESSAGE_SERVER_H_