Add CompositeMachMessageServer and its test

util/mach/mach_message_server.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #ifndef CRASHPAD_UTIL_MACH_MACH_MESSAGE_SERVER_H_
 #define CRASHPAD_UTIL_MACH_MACH_MESSAGE_SERVER_H_
 
 #include <mach/mach.h>
 
+#include <set>
+
 #include "base/basictypes.h"
 
 namespace crashpad {
 
 //! \brief Runs a Mach message server to handle a Mach RPC request for MIG
 //!     servers.
 //!
 //! The principal entry point to this interface is the static Run() method.
 class MachMessageServer {
  public:
@@ skipping 31 matching lines @@
     //!
     //! \return `true` on success and `false` on failure, although the caller
     //!     ignores the return value. However, the return code to be included in
     //!     the reply message should be set as `mig_reply_error_t::RetCode`. The
     //!     non-`void` return value is used for increased compatibility with
     //!     MIG-generated functions.
     virtual bool MachMessageServerFunction(const mach_msg_header_t* in,
                                            mach_msg_header_t* out,
                                            bool* destroy_complex_request) = 0;
 
+    //! \return The set of request message Mach message IDs that
+    //!     MachMessageServerFunction() is able to handle.
+    virtual std::set<mach_msg_id_t> MachMessageServerRequestIDs() = 0;
+
     //! \return The expected or maximum size, in bytes, of a request message to
     //!     be received as the \a in parameter of MachMessageServerFunction().
     virtual mach_msg_size_t MachMessageServerRequestSize() = 0;
 
     //! \return The maximum size, in bytes, of a reply message to be sent via
     //!     the \a out parameter of MachMessageServerFunction(). This value does
     //!     not need to include the size of any trailer to be sent with the
     //!     message.
     virtual mach_msg_size_t MachMessageServerReplySize() = 0;
 
@@ skipping 97 matching lines @@
                                ReceiveLarge receive_large,
                                mach_msg_timeout_t timeout_ms);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(MachMessageServer);
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_MACH_MACH_MESSAGE_SERVER_H_