Remove all blimp engine code

blimp/engine/app/settings_manager.h

-// Copyright 2016 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 BLIMP_ENGINE_APP_SETTINGS_MANAGER_H_
-#define BLIMP_ENGINE_APP_SETTINGS_MANAGER_H_
-
-#include "base/macros.h"
-#include "base/observer_list.h"
-#include "blimp/engine/app/engine_settings.h"
-#include "blimp/net/blimp_message_processor.h"
-#include "content/public/browser/render_view_host.h"
-
-namespace blimp {
-namespace engine {
-
-// This class is owned by the BlimpBrowserMainParts and manages the
-// |EngineSettings| that can be set on the engine.
-class SettingsManager {
- public:
-  // An observer interested in knowing when the engine settings have changed.
-  class Observer {
-   public:
-    // Called when the WebPreferences have changed. See content::WebPreferences.
-    virtual void OnWebPreferencesChanged() {}
-  };
-
-  SettingsManager();
-  ~SettingsManager();
-
-  void AddObserver(Observer* observer);
-  void RemoveObserver(Observer* observer);
-
-  // Called to update the WebPreferences.
-  void UpdateWebkitPreferences(content::WebPreferences* prefs);
-
-  const EngineSettings& GetEngineSettings() const;
-  void UpdateEngineSettings(const EngineSettings& settings);
-
- private:
-  EngineSettings settings_;
-
-  base::ObserverList<Observer> observer_list_;
-
-  DISALLOW_COPY_AND_ASSIGN(SettingsManager);
-};
-
-}  // namespace engine
-}  // namespace blimp
-
-#endif  // BLIMP_ENGINE_APP_SETTINGS_MANAGER_H_