chromium/chrome/browser/ui/blocked_content/tab_under_navigation_throttle.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 CHROME_BROWSER_UI_BLOCKED_CONTENT_TAB_UNDER_NAVIGATION_THROTTLE_H_
#define CHROME_BROWSER_UI_BLOCKED_CONTENT_TAB_UNDER_NAVIGATION_THROTTLE_H_

#include <memory>

#include "base/feature_list.h"
#include "content/public/browser/navigation_throttle.h"

namespace content {
class NavigationHandle;
}

constexpr char kBlockTabUnderFormatMessage[] = …;

// TODO(crbug.com/40623730): Remove this.
BASE_DECLARE_FEATURE(kBlockTabUnders);

// This class blocks navigations that we've classified as tab-unders. It does so
// by communicating with the popup opener tab helper.
//
// Currently, navigations are considered tab-unders if:
// 1. It is a navigation that is "suspicious"
//    a. It has no user gesture.
//    b. It is renderer-initiated.
//    c. It is cross site to the last committed URL in the tab.
//    d. The navigation started in the background.
// 2. The tab has opened a popup and hasn't received a user gesture since then.
//    This information is tracked by the PopupOpenerTabHelper.
//
//  TODO(csharrison): Unfortunately, the provision that a navigation must start
//  in the background to be considered a tab-under restricts the scope of the
//  intervention. For instance, popups that do not completely hide the original
//  page may cause subsequent tab-under navigations to occur while visible (not
//  compeltely backgrounded). See https://crbug.com/733736.
//
//  For now, we allow these tab-unders because this pattern seems to be
//  legitimate for some cases (like auth).
class TabUnderNavigationThrottle : public content::NavigationThrottle { … };

#endif  // CHROME_BROWSER_UI_BLOCKED_CONTENT_TAB_UNDER_NAVIGATION_THROTTLE_H_