Remove all blimp engine code

blimp/engine/feature/engine_settings_feature.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_FEATURE_ENGINE_SETTINGS_FEATURE_H_
-#define BLIMP_ENGINE_FEATURE_ENGINE_SETTINGS_FEATURE_H_
-
-#include "base/macros.h"
-#include "base/observer_list.h"
-#include "blimp/net/blimp_message_processor.h"
-#include "content/public/browser/render_view_host.h"
-
-namespace blimp {
-class EngineSettingsMessage;
-
-namespace engine {
-class SettingsManager;
-
-// The feature is used to receive global settings from the client.
-class EngineSettingsFeature : public BlimpMessageProcessor {
- public:
-  explicit EngineSettingsFeature(SettingsManager* settings_manager);
-  ~EngineSettingsFeature() override;
-
-  // BlimpMessageProcessor implementation.
-  void ProcessMessage(std::unique_ptr<BlimpMessage> message,
-                      const net::CompletionCallback& callback) override;
-
- private:
-  void ProcessSettings(const EngineSettingsMessage& settings);
-
-  SettingsManager* settings_manager_;
-
-  DISALLOW_COPY_AND_ASSIGN(EngineSettingsFeature);
-};
-
-}  // namespace engine
-}  // namespace blimp
-
-#endif  // BLIMP_ENGINE_FEATURE_ENGINE_SETTINGS_FEATURE_H_