Remove files that are no longer used in the Port EDK.

mojo/edk/system/message_in_transit_queue.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/edk/system/message_in_transit_queue.h"
-
-#include "base/logging.h"
-
-namespace mojo {
-namespace edk {
-
-MessageInTransitQueue::MessageInTransitQueue() {
-}
-
-MessageInTransitQueue::~MessageInTransitQueue() {
-  if (!IsEmpty()) {
-    DVLOG(1) << "Destroying nonempty message queue";
-    Clear();
-  }
-}
-
-void MessageInTransitQueue::Clear() {
-  for (auto* message : queue_)
-    delete message;
-  queue_.clear();
-}
-
-void MessageInTransitQueue::Swap(MessageInTransitQueue* other) {
-  queue_.swap(other->queue_);
-}
-
-}  // namespace edk
-}  // namespace mojo