Mojo: Factor MessageInTransit secondary buffer stuff out into a separate class.

mojo/system/raw_channel_unittest.cc

 // 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.
 
 #include "mojo/system/raw_channel.h"
 
 #include <stdint.h>
 
 #include <vector>
 
@@ skipping 22 matching lines @@
 namespace system {
 namespace {
 
 scoped_ptr<MessageInTransit> MakeTestMessage(uint32_t num_bytes) {
   std::vector<unsigned char> bytes(num_bytes, 0);
   for (size_t i = 0; i < num_bytes; i++)
     bytes[i] = static_cast<unsigned char>(i + num_bytes);
   return make_scoped_ptr(
       new MessageInTransit(MessageInTransit::kTypeMessagePipeEndpoint,
                            MessageInTransit::kSubtypeMessagePipeEndpointData,
-                           num_bytes, 0, bytes.empty() ? NULL : &bytes[0]));
+                           num_bytes, bytes.empty() ? NULL : &bytes[0]));
 }
 
 bool CheckMessageData(const void* bytes, uint32_t num_bytes) {
   const unsigned char* b = static_cast<const unsigned char*>(bytes);
   for (uint32_t i = 0; i < num_bytes; i++) {
     if (b[i] != static_cast<unsigned char>(i + num_bytes))
       return false;
   }
   return true;
 }
@@ skipping 615 matching lines @@
 
   EXPECT_FALSE(rc->WriteMessage(MakeTestMessage(1)));
 
   // Wait for the delegate, which will shut the |RawChannel| down.
   delegate.Wait();
 }
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo