Not working on new wnidow

[stivencyj92]

Overall, it works well in the same page.
However, if the code should run on the new window, then it won't work.
And I found that if the devtool opens as the new window, the code can't feagure out whether it opened or closed.

[Sindre Sorhus]

This is a document limitation: https://github.com/sindresorhus/devtools-detect#caveats