chromium/components/metrics/content/subprocess_metrics_provider.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_METRICS_CONTENT_SUBPROCESS_METRICS_PROVIDER_H_
#define COMPONENTS_METRICS_CONTENT_SUBPROCESS_METRICS_PROVIDER_H_

#include <map>
#include <memory>

#include "base/memory/ref_counted.h"
#include "base/memory/scoped_refptr.h"
#include "base/memory/weak_ptr.h"
#include "base/metrics/statistics_recorder.h"
#include "base/scoped_multi_source_observation.h"
#include "base/task/task_runner.h"
#include "base/threading/thread_checker.h"
#include "components/metrics/metrics_provider.h"
#include "content/public/browser/browser_child_process_observer.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/render_process_host_creation_observer.h"
#include "content/public/browser/render_process_host_observer.h"

namespace base {
class PersistentHistogramAllocator;
}

namespace metrics {

// SubprocessMetricsProvider gathers and merges histograms stored in shared
// memory segments between processes. Merging occurs when a process exits,
// when metrics are being collected for upload, or when something else needs
// combined metrics (such as the chrome://histograms page).
// TODO(crbug.com/40213327): Do not inherit MetricsProvider.
class SubprocessMetricsProvider
    : public MetricsProvider,
      public base::StatisticsRecorder::HistogramProvider,
      public content::BrowserChildProcessObserver,
      public content::RenderProcessHostCreationObserver,
      public content::RenderProcessHostObserver { … };

}  // namespace metrics

#endif  // COMPONENTS_METRICS_CONTENT_SUBPROCESS_METRICS_PROVIDER_H_