Mojo: Refactor some message pipe stuff.

mojo/system/message_pipe.cc

 // Copyright 2013 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/message_pipe.h"
 
 #include "base/logging.h"
 #include "mojo/system/channel.h"
 #include "mojo/system/dispatcher.h"
 #include "mojo/system/local_message_pipe_endpoint.h"
@@ skipping 96 matching lines @@
 
   endpoints_[port]->RemoveWaiter(waiter);
 }
 
 MojoResult MessagePipe::EnqueueMessage(
     unsigned port,
     MessageInTransit* message,
     const std::vector<Dispatcher*>* dispatchers) {
   DCHECK(port == 0 || port == 1);
   DCHECK(message);
+  DCHECK(!dispatchers || !dispatchers->empty());
 
   if (message->type() == MessageInTransit::kTypeMessagePipe) {
     DCHECK(!dispatchers);
     return HandleControlMessage(port, message);
   }
 
   DCHECK_EQ(message->type(), MessageInTransit::kTypeMessagePipeEndpoint);
 
   base::AutoLock locker(lock_);
   DCHECK(endpoints_[GetPeerPort(port)].get());
 
   // The destination port need not be open, unlike the source port.
   if (!endpoints_[port].get()) {
     message->Destroy();
     return MOJO_RESULT_FAILED_PRECONDITION;
   }
 
-  MojoResult result = endpoints_[port]->CanEnqueueMessage(message, dispatchers);
-  if (result != MOJO_RESULT_OK) {
-    message->Destroy();
-    return result;
-  }
-
-  if (dispatchers) {
-    DCHECK(!dispatchers->empty());
-
-    std::vector<scoped_refptr<Dispatcher> > replacement_dispatchers;
-    for (size_t i = 0; i < dispatchers->size(); i++) {
-      replacement_dispatchers.push_back(
-          (*dispatchers)[i]->CreateEquivalentDispatcherAndCloseNoLock());
-    }
-
-    endpoints_[port]->EnqueueMessage(message, &replacement_dispatchers);
-  } else {
-    endpoints_[port]->EnqueueMessage(message, NULL);
-  }
-
-  return MOJO_RESULT_OK;
+  return endpoints_[port]->EnqueueMessage(message, dispatchers);
 }
 
 void MessagePipe::Attach(unsigned port,
                          scoped_refptr<Channel> channel,
                          MessageInTransit::EndpointId local_id) {
   DCHECK(port == 0 || port == 1);
   DCHECK(channel.get());
   DCHECK_NE(local_id, MessageInTransit::kInvalidEndpointId);
 
   base::AutoLock locker(lock_);
@@ skipping 46 matching lines @@
       rv = MOJO_RESULT_UNKNOWN;
       break;
   }
 
   message->Destroy();
   return rv;
 }
 
 }  // namespace system
 }  // namespace mojo