在manifest.json中设置"icons"键.

browser_action.icons键是工具栏中显示的键(可能仅使用16、24和32尺寸的图像，请参见浏览器操作).

Set "icons" key in manifest.json.

The browser_action.icons key is what gets displayed in the toolbar (and will probably only use 16, 24, and 32 sized images, see browserAction).

chrome://extensions中显示的一个是***icons键.在清单文档中，查找第6个条目，以便清单具有顶层条目，例如:

The one displayed in chrome://extensions is a top level icons key. In the manifest documentation, look for the 6th entry, so that your manifest has an top-level entry, like:

{
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  }
}