How to set document.visibilityState in cef?

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When tab switched, I want to set document.visibilityState to 'hidden' in old page.
I tried this way:
1. ExecuteJavascript in console,

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document.visibilityState = 'hidden'

it fails as the attribute is readonly.
2. Use

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browser->GetHost()->WasHidden(true);

it no effects. I read the comment,

Notify the browser that it has been hidden or shown. Layouting and CefRenderHandler::OnPaint notification will stop when the browser is hidden. This method is only used when window rendering is disabled.

but I don't know how to disable rendering.
3.Use

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SetWindowPos(hwnd, NULL, 0, 0, 0, 0, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);

it works, but when tab switch back, use

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ShowWindow(hwnd, SW_SHOW);

and

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MoveWindow(hwnd, rect.x(), rect.y(), rect.width(), rect.height(), true);

to restore, there has a black background show rapidly, then show normal view. The black backgournd is a big problem when switch frequently.

So, what the correct way to set document.visibilityState?