content/browser/xr/metrics/session_timer.cc

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/xr/metrics/session_timer.h"

#include "base/metrics/histogram_functions.h"

namespace content {

SessionTimer::SessionTimer() = default;

SessionTimer::~SessionTimer() {
  StopSession();
}

void SessionTimer::StartSession() {
  DCHECK(start_time_.is_null())
      << "Must stop existing session before starting a new one";

  start_time_ = base::Time::Now();
}

void SessionTimer::StopSession() {
  if (start_time_.is_null()) {
    return;
  }
  // Calculate the duration of the session.
  base::TimeDelta session_duration = base::Time::Now() - start_time_;
  if (!session_duration.is_zero()) {
    // TODO(https://crbug.com/1056930): Consider renaming the timers to
    // something that indicates both that these also record AR, and that these
    // are no longer "suffixed" histograms.
    base::UmaHistogramCustomTimes("VRSessionTime.WebVR", session_duration,
                                  base::TimeDelta(), base::Hours(5), 100);
  }

  // Clear out start time.
  start_time_ = base::Time();
}

}  // namespace content