Remove mojo/apps/js, it is unused

mojo/apps/js/mojo_bridge_module.h

-// 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.
-
-#ifndef MOJO_APPS_JS_MOJO_MODULE_H_
-#define MOJO_APPS_JS_MOJO_MODULE_H_
-
-#include "gin/gin_export.h"
-#include "v8/include/v8.h"
-
-namespace mojo {
-namespace apps {
-
-class JSApp;
-
-// The JavaScript "mojo/apps/js/mojo" module depends on this built-in module.
-// It provides the bridge between the JSApp class and JavaScript.
-
-class MojoInternals {
- public:
-  static const char kModuleName[];
-  static v8::Local<v8::Value> GetModule(JSApp* js_app, v8::Isolate* isolate);
-};
-
-}  // namespace apps
-}  // namespace mojo
-
-#endif  // MOJO_APPS_JS_MOJO_MODULE_H_