chromium/third_party/blink/renderer/platform/scheduler/public/frame_status.h

// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_PUBLIC_FRAME_STATUS_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_PUBLIC_FRAME_STATUS_H_

#include "third_party/blink/renderer/platform/platform_export.h"

namespace blink {
class FrameScheduler;

namespace scheduler {

// This enum is used for histogram and should not be renumbered.
// This enum should be kept in sync with FrameSchedulingLifecycleState and
// FrameOriginState.
//
// There are three main states:
// VISIBLE describes frames which are visible to the user (both page and frame
// are visible).
// Without this service frame would have had kBackgrounded state.
// HIDDEN describes frames which are out of viewport but the page is visible
// to the user.
// BACKGROUND describes frames in background pages.
//
// There are four auxillary states:
// VISIBLE_SERVICE describes frames which are treated as visible to the user
// but it is a service (e.g. audio) which forces the page to be foregrounded.
// HIDDEN_SERVICE describes offscreen frames in pages which are treated as
// foregrounded due to a presence of a service (e.g. audio playing).
// BACKGROUND_EXEMPT_SELF describes background frames which are
// exempted from background throttling due to a special conditions being met
// for this frame.
// BACKGROUND_EXEMPT_kOther describes background frames which are exempted from
// background throttling due to other frames granting an exemption for
// the whole page.
//
// Note that all these seven states are disjoint, e.g, when calculating
// a metric for background BACKGROUND, BACKGROUND_EXEMPT_SELF and
// BACKGROUND_EXEMPT_kOther should be added together.
enum class FrameStatus { … };

PLATFORM_EXPORT FrameStatus GetFrameStatus(FrameScheduler* frame_scheduler);

}  // namespace scheduler
}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_SCHEDULER_PUBLIC_FRAME_STATUS_H_