chrome/browser/page_load_metrics/observers/previews_ukm_observer.h

// 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 CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_PREVIEWS_UKM_OBSERVER_H_
#define CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_PREVIEWS_UKM_OBSERVER_H_

#include "base/macros.h"
#include "base/sequence_checker.h"
#include "components/optimization_guide/proto/hints.pb.h"
#include "components/page_load_metrics/browser/page_load_metrics_observer.h"

namespace content {
class NavigationHandle;
}  // namespace content

namespace previews {

// Observer responsible for appending previews information to the PLM UKM
// report.
class PreviewsUKMObserver : public page_load_metrics::PageLoadMetricsObserver {
 public:
  PreviewsUKMObserver();

  PreviewsUKMObserver(const PreviewsUKMObserver&) = delete;
  PreviewsUKMObserver& operator=(const PreviewsUKMObserver&) = delete;

  ~PreviewsUKMObserver() override;

  // page_load_metrics::PageLoadMetricsObserver:
  ObservePolicy OnStart(content::NavigationHandle* navigation_handle,
                        const GURL& currently_committed_url,
                        bool started_in_foreground) override;
  ObservePolicy OnCommit(content::NavigationHandle* navigation_handle,
                         ukm::SourceId source_id) override;
  ObservePolicy FlushMetricsOnAppEnterBackground(
      const page_load_metrics::mojom::PageLoadTiming& timing) override;
  ObservePolicy OnHidden(
      const page_load_metrics::mojom::PageLoadTiming& timing) override;
  void OnComplete(
      const page_load_metrics::mojom::PageLoadTiming& timing) override;

 protected:
  // Returns true if data saver feature is enabled in Chrome. Virtualized for
  // testing.
  virtual bool IsDataSaverEnabled(
      content::NavigationHandle* navigation_handle) const;

 private:
  void RecordPreviewsTypes();

  bool save_data_enabled_ = false;

  SEQUENCE_CHECKER(sequence_checker_);
};

}  // namespace previews

#endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_PREVIEWS_UKM_OBSERVER_H_