It's going to be removed from Chromium, see https://crbug.com/812523.

/cc @electron/code-owners 
shell/browser/api/electron_api_app.cc
base::BindRepeating(&Browser::SetUserActivity, browser))
      .SetMethod("getCurrentActivityType",
                 base::BindRepeating(&Browser::GetCurrentActivityType, browser))
      .SetMethod(
          "invalidateCurrentActivity",
          base::BindRepeating(&Browser::InvalidateCurrentActivity, browser))
      .SetMethod("resignCurrentActivity",
                 base::BindRepeating(&Browser::ResignCurrentActivity, browser))
      .SetMethod("updateCurrentActivity",
                 base::BindRepeating(&Browser::UpdateCurrentActivity, browser))
      .SetMethod("moveToApplicationsFolder", &App::MoveToApplicationsFolder)
      .SetMethod("isInApplicationsFolder", &App::IsInApplicationsFolder)
      .SetMethod("setActivationPolicy", &App::SetActivationPolicy)
#endif
      .SetMethod("setAboutPanelOptions",
                 base::BindRepeating(&Browser::SetAboutPanelOptions, browser))
      .SetMethod("showAboutPanel",
                 base::BindRepeating(&Browser::ShowAboutPanel, browser))
#if defined(OS_MACOSX) || defined(OS_WIN)
      .SetMethod("showEmojiPanel",
                 base::BindRepeating(&Browser::ShowEmojiPanel, browser))
#endif
#if defined(OS_WIN)
      .SetMethod("setUserTasks",
                 base::BindRepeating(&Browser::SetUserTasks, browser))
      .SetMethod("getJumpListSettings", &App::GetJumpListSettings)
      .SetMethod("setJumpList", &App::SetJumpList)
#endif
#if defined(OS_LINUX)
      .SetMethod("isUnityRunning",