text: // Copyright 2017 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 COMPONENTS_DOWNLOAD_INTERNAL_BACKGROUND_SERVICE_LOG_SINK_H_
  #define COMPONENTS_DOWNLOAD_INTERNAL_BACKGROUND_SERVICE_LOG_SINK_H_
  
  #include "components/download/internal/background_service/constants.h"
  #include "components/download/internal/background_service/startup_status.h"
  #include "components/download/public/background_service/download_params.h"
  
  namespace download {
  
  struct Entry;
  
  // A destination for all interesting events from internal components.
  class LogSink {
   public:
    virtual ~LogSink() = default;
  
    // To be called whenever the StartupStatus/Controller::State changes.
    virtual void OnServiceStatusChanged() = 0;
  
    // To be called whenever the list of underlying Entry objects is ready to be
    // queried by external log entities.
    virtual void OnServiceDownloadsAvailable() = 0;
  
    // To be called whenever the state the download represented by |guid| changes.
    virtual void OnServiceDownloadChanged(const std::string& guid) = 0;
  
    // To be called whenever a download fails.
    virtual void OnServiceDownloadFailed(CompletionType completion_type,
                                         const Entry& entry) = 0;
  
    // To be called whenever a request has been made of the download service.
    virtual void OnServiceRequestMade(
        DownloadClient client,
        const std::string& guid,
        DownloadParams::StartResult start_result) = 0;
  };
  
  }  // namespace download
  
  #endif  // COMPONENTS_DOWNLOAD_INTERNAL_BACKGROUND_SERVICE_LOG_SINK_H_
  