Rationalize Dart mojo and sky package structure

mojo/public/dart/src/timer_queue.dart

-// 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.
-
-part of internal;
-
-class Timeout implements Comparable<Timeout> {
-  int deadline; // milliseconds since the Unix epoch.
-  SendPort port;
-
-  Timeout(this.port, this.deadline);
-
-  int compareTo(Timeout other) => deadline - other.deadline;
-}
-
-class TimerQueue {
-  SplayTreeSet _set;
-  Timeout _nextTimer;
-
-  TimerQueue() : _set = new SplayTreeSet();
-
-  void updateTimer(SendPort port, int deadline) {
-    var removedTimeout = null;
-    _set.removeWhere((timeout) {
-      if (timeout.port == port) {
-        removedTimeout = timeout;
-        return true;
-      }
-      return false;
-    });
-
-    if ((removedTimeout == null) && (deadline >= 0)) {
-      _set.add(new Timeout(port, deadline));
-    } else {
-      if (deadline > 0) {
-        removedTimeout.deadline = deadline;
-        _set.add(removedTimeout);
-      }
-    }
-
-    if (_set.isNotEmpty) {
-      _nextTimer = _set.first;
-    } else {
-      _nextTimer = null;
-    }
-  }
-
-  void removeCurrent() => updateTimer(currentPort, -1);
-
-  bool get hasTimer => _nextTimer != null;
-  int get currentTimeout => _nextTimer.deadline;
-  SendPort get currentPort => _nextTimer.port;
-}