Mojo C++ bindings: remove the utility/ folder.

mojo/public/cpp/utility/run_loop_handler.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_PUBLIC_CPP_UTILITY_RUN_LOOP_HANDLER_H_
-#define MOJO_PUBLIC_CPP_UTILITY_RUN_LOOP_HANDLER_H_
-
-#include "mojo/public/cpp/system/core.h"
-
-namespace mojo {
-
-// Used by RunLoop to notify when a handle is either ready or has become
-// invalid.
-class RunLoopHandler {
- public:
-  virtual void OnHandleReady(const Handle& handle) = 0;
-  virtual void OnHandleError(const Handle& handle, MojoResult result) = 0;
-
- protected:
-  virtual ~RunLoopHandler() {}
-};
-
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_UTILITY_RUN_LOOP_HANDLER_H_