Remove mojo/apps/js, it is unused

mojo/apps/js/application_delegate_impl.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_CONTENT_HANDLER_H_
-#define MOJO_APPS_JS_CONTENT_HANDLER_H_
-
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/scoped_vector.h"
-#include "mojo/public/cpp/application/application_delegate.h"
-#include "mojo/public/cpp/system/message_pipe.h"
-
-namespace mojo {
-
-class ApplcationImpl;
-
-namespace apps {
-
-class ApplicationDelegateImpl;
-class JSApp;
-
-// Manages the JSApps started by this content handler. This class owns the one
-// reference to the Mojo shell. JSApps post a task to the content handler's
-// thread to connect to a service or to quit.
-//
-// The lifetime each JSApp is defined by its entry in AppVector. When the entry
-// is removed ("erased") by QuitJSApp(), the JSApp is destroyed.
-
-class ApplicationDelegateImpl : public ApplicationDelegate {
- public:
-  ApplicationDelegateImpl();
-  ~ApplicationDelegateImpl() override;
-
-  // Add app to the AppVector and call its Start() method.
-  void StartJSApp(scoped_ptr<JSApp> app);
-
-  // Remove app from the AppVector; destroys the app.
-  void QuitJSApp(JSApp *app);
-
-  void ConnectToService(ScopedMessagePipeHandle pipe_handle,
-                        const std::string& application_url,
-                        const std::string& interface_name);
-
- protected:
-  // ApplicationDelegate:
-  void Initialize(ApplicationImpl* app) override;
-
- private:
-  typedef ScopedVector<JSApp> AppVector;
-  ApplicationImpl* application_impl_;
-  AppVector app_vector_;
-};
-
-}  // namespace apps
-}  // namespace mojo
-
-#endif  // MOJO_APPS_JS_CONTENT_HANDLER_H_