此示例将光标更改为在选择图像时等待，并在10秒后恢复。

备注：
如果您打开了DevTools，则在您移动光标之前，它不会返回。

background.js

chrome.runtime.onInstalled.addListener(() => {
  chrome.contextMenus.create({
    id: "hoge",
    title: "Select image.",
    type: "normal",
    contexts: ["image"]
  });
});

const cursorToWait = () => {
  const style = document.createElement("style");
  style.id = "corsor_wait";
  style.innerHTML = "* {cursor: wait;}"
  document.head.insertBefore(style, null);
};

const restoreCursor = () => {
  document.getElementById("corsor_wait").remove();
};

chrome.contextMenus.onClicked.addListener(async () => {
  const tabs = await chrome.tabs.query({ active: true, currentWindow: true });
  await chrome.scripting.executeScript({
    target: { tabId: tabs[0].id },
    function: cursorToWait
  });
  await new Promise(r => setTimeout(r, 10000));
  await chrome.scripting.executeScript({
    target: { tabId: tabs[0].id },
    function: restoreCursor
  });
});

manifest.json

{
  "name": "hoge",
  "version": "1.0",
  "manifest_version": 3,
  "permissions": [
    "contextMenus",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "service_worker": "background.js"
  }
}

在Chrome扩展Manifest V3中，使用内容脚本并将鼠标光标置于content.js文件中。

清单.json

"manifest_version": 3,
"content_scripts": [
    {
      "matches": ["*://*/*"],
      "js": ["js/content.js"],
      "run_at": "document_end"
    }
  ],

内容.js**

document.body.style.cursor = 'wait';

您可以使用消息传递来了解选项卡的状态：https://developer.chrome.com/docs/extensions/mv3/messaging/