Revert "Move mojo edk into mojo/edk"

mojo/edk/system/simple_dispatcher.h

-// 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.
-
-#ifndef MOJO_EDK_SYSTEM_SIMPLE_DISPATCHER_H_
-#define MOJO_EDK_SYSTEM_SIMPLE_DISPATCHER_H_
-
-#include <list>
-
-#include "base/macros.h"
-#include "mojo/edk/system/dispatcher.h"
-#include "mojo/edk/system/system_impl_export.h"
-#include "mojo/edk/system/waiter_list.h"
-
-namespace mojo {
-namespace system {
-
-// A base class for simple dispatchers. "Simple" means that there's a one-to-one
-// correspondence between handles and dispatchers (see the explanatory comment
-// in core.cc). This class implements the standard waiter-signalling mechanism
-// in that case.
-class MOJO_SYSTEM_IMPL_EXPORT SimpleDispatcher : public Dispatcher {
- protected:
-  SimpleDispatcher();
-  virtual ~SimpleDispatcher();
-
-  // To be called by subclasses when the state changes (so
-  // |GetHandleSignalsStateImplNoLock()| should be checked again). Must be
-  // called under lock.
-  void HandleSignalsStateChangedNoLock();
-
-  // |Dispatcher| protected methods:
-  virtual void CancelAllWaitersNoLock() override;
-  virtual MojoResult AddWaiterImplNoLock(
-      Waiter* waiter,
-      MojoHandleSignals signals,
-      uint32_t context,
-      HandleSignalsState* signals_state) override;
-  virtual void RemoveWaiterImplNoLock(
-      Waiter* waiter,
-      HandleSignalsState* signals_state) override;
-
- private:
-  // Protected by |lock()|:
-  WaiterList waiter_list_;
-
-  DISALLOW_COPY_AND_ASSIGN(SimpleDispatcher);
-};
-
-}  // namespace system
-}  // namespace mojo
-
-#endif  // MOJO_EDK_SYSTEM_SIMPLE_DISPATCHER_H_