Remove mojo/apps/js, it is unused

mojo/apps/js/js_app.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_JS_APP_H_
-#define MOJO_APPS_JS_JS_APP_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/threading/thread.h"
-#include "gin/public/isolate_holder.h"
-#include "gin/shell_runner.h"
-#include "mojo/apps/js/mojo_runner_delegate.h"
-#include "mojo/services/public/interfaces/content_handler/content_handler.mojom.h"
-
-namespace mojo {
-namespace apps {
-
-class JSApp;
-class ApplicationDelegateImpl;
-
-// Each JavaScript app started by content handler runs on its own thread and
-// in its own V8 isolate. This class represents one running JS app.
-
-class JSApp {
- public:
-  JSApp(ApplicationDelegateImpl* app_delegate_impl);
-  virtual ~JSApp();
-
-  // Launch this app on a new thread. This method can be called on any thread.
-  // This method causes Load() and then Run() to run on a new thread.
-  bool Start();
-
-  // Subclasses must return the JS source code for this app's main script and
-  // the filename or URL that identifies the script's origin. This method will
-  // be called from this app's thread.
-  virtual bool Load(std::string* source, std::string* file_name) = 0;
-
-  // Called by the JS mojo module to quit this JS app. See mojo.js.
-  void Quit();
-
-  // Called by the JS mojo module to connect to a Mojo service.
-  Handle ConnectToService(const std::string& application_url,
-                          const std::string& interface_name);
-
- private:
-  void Run();
-  void Terminate();
-
-  // Used to CHECK that we're running on the correct thread.
-  bool on_app_delegate_impl_thread() const;
-  bool on_js_app_thread() const;
-
-  ApplicationDelegateImpl* app_delegate_impl_;
-  base::Thread thread_;
-  scoped_refptr<base::SingleThreadTaskRunner> app_delegate_impl_task_runner_;
-  scoped_refptr<base::SingleThreadTaskRunner> js_app_task_runner_;
-  MojoRunnerDelegate runner_delegate_;
-  scoped_ptr<gin::IsolateHolder> isolate_holder_;
-  scoped_ptr<gin::ShellRunner> shell_runner_;
-
-  DISALLOW_COPY_AND_ASSIGN(JSApp);
-};
-
-}  // namespace apps
-}  // namespace mojo
-
-#endif  // MOJO_APPS_JS_JS_APP_H_