Este bookmarlet funciona nos sites do Google / Youtube a partir de agosto de 2019 (testado no Chrome e Firefox):
javascript: function enableContextMenu(aggressive = false) { void(document.ondragstart=null); void(document.onselectstart=null); void(document.onclick=null); void(document.onmousedown=null); void(document.onmouseup=null); void(document.body.oncontextmenu=null); enableRightClickLight(document); if (aggressive) { enableRightClick(document); removeContextMenuOnAll("body"); removeContextMenuOnAll("img"); removeContextMenuOnAll("td"); } } function removeContextMenuOnAll(tagName) { var elements = document.getElementsByTagName(tagName); for (var i = 0; i < elements.length; i++) { enableRightClick(elements[i]); } } function enableRightClickLight(el) { el || (el = document); el.addEventListener("contextmenu", bringBackDefault, true); } function enableRightClick(el) { el || (el = document); el.addEventListener("contextmenu", bringBackDefault, true); el.addEventListener("dragstart", bringBackDefault, true); el.addEventListener("selectstart", bringBackDefault, true); el.addEventListener("click", bringBackDefault, true); el.addEventListener("mousedown", bringBackDefault, true); el.addEventListener("mouseup", bringBackDefault, true); } function restoreRightClick(el) { el || (el = document); el.removeEventListener("contextmenu", bringBackDefault, true); el.removeEventListener("dragstart", bringBackDefault, true); el.removeEventListener("selectstart", bringBackDefault, true); el.removeEventListener("click", bringBackDefault, true); el.removeEventListener("mousedown", bringBackDefault, true); el.removeEventListener("mouseup", bringBackDefault, true); } function bringBackDefault(event) { event.returnValue = true; (typeof event.stopPropagation === 'function') && event.stopPropagation(); (typeof event.cancelBubble === 'function') && event.cancelBubble(); } enableContextMenu();
Para sites mais pesados, defina / passe agressivo para true (isso desativará a maioria dos manipuladores de eventos e, portanto, a interação com a página):
javascript: function enableContextMenu(aggressive = true) { void(document.ondragstart=null); void(document.onselectstart=null); void(document.onclick=null); void(document.onmousedown=null); void(document.onmouseup=null); void(document.body.oncontextmenu=null); enableRightClickLight(document); if (aggressive) { enableRightClick(document); removeContextMenuOnAll("body"); removeContextMenuOnAll("img"); removeContextMenuOnAll("td"); } } function removeContextMenuOnAll(tagName) { var elements = document.getElementsByTagName(tagName); for (var i = 0; i < elements.length; i++) { enableRightClick(elements[i]); } } function enableRightClickLight(el) { el || (el = document); el.addEventListener("contextmenu", bringBackDefault, true); } function enableRightClick(el) { el || (el = document); el.addEventListener("contextmenu", bringBackDefault, true); el.addEventListener("dragstart", bringBackDefault, true); el.addEventListener("selectstart", bringBackDefault, true); el.addEventListener("click", bringBackDefault, true); el.addEventListener("mousedown", bringBackDefault, true); el.addEventListener("mouseup", bringBackDefault, true); } function restoreRightClick(el) { el || (el = document); el.removeEventListener("contextmenu", bringBackDefault, true); el.removeEventListener("dragstart", bringBackDefault, true); el.removeEventListener("selectstart", bringBackDefault, true); el.removeEventListener("click", bringBackDefault, true); el.removeEventListener("mousedown", bringBackDefault, true); el.removeEventListener("mouseup", bringBackDefault, true); } function bringBackDefault(event) { event.returnValue = true; (typeof event.stopPropagation === 'function') && event.stopPropagation(); (typeof event.cancelBubble === 'function') && event.cancelBubble(); } enableContextMenu();