Tests that forced dark mode can be emulated.
<p>Baseline:
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAL0lEQVR4nOzNAQkAAAgDMBH7V74xBNkKbJLUha4jYrFYLBaLxWKxWCwWi8Xij/ECAAD//0qL10gAAAAGSURBVAMAvKMDUHq+e0IAAAAASUVORK5CYII=">
<p>Emulating auto dark mode: true
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAMElEQVR4nOzNAQkAAAgDMBETvH9YYwiyFdgkqQtdR8RisVgsFovFYrFYLBaLxR/jBQAA///hmYMyAAAABklEQVQDADzNAIkBjBLgAAAAAElFTkSuQmCC">
<p>Emulating auto dark mode: true
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAMElEQVR4nOzNAQkAAAgDMBETvH9YYwiyFdgkqQtdR8RisVgsFovFYrFYLBaLxR/jBQAA///hmYMyAAAABklEQVQDADzNAIkBjBLgAAAAAElFTkSuQmCC">
<p>Emulating auto dark mode: false
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAL0lEQVR4nOzNAQkAAAgDMBH7V74xBNkKbJLUha4jYrFYLBaLxWKxWCwWi8Xij/ECAAD//0qL10gAAAAGSURBVAMAvKMDUHq+e0IAAAAASUVORK5CYII=">
<p>Emulating auto dark mode: true
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAMElEQVR4nOzNAQkAAAgDMBETvH9YYwiyFdgkqQtdR8RisVgsFovFYrFYLBaLxR/jBQAA///hmYMyAAAABklEQVQDADzNAIkBjBLgAAAAAElFTkSuQmCC">
<p>Emulating auto dark mode: undefined
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAL0lEQVR4nOzNAQkAAAgDMBH7V74xBNkKbJLUha4jYrFYLBaLxWKxWCwWi8Xij/ECAAD//0qL10gAAAAGSURBVAMAvKMDUHq+e0IAAAAASUVORK5CYII=">
<p>Emulating auto dark mode: true
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAMElEQVR4nOzNAQkAAAgDMBETvH9YYwiyFdgkqQtdR8RisVgsFovFYrFYLBaLxR/jBQAA///hmYMyAAAABklEQVQDADzNAIkBjBLgAAAAAElFTkSuQmCC">
<p>Navigating&mldr;
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACgAAAAoCAIAAAADnC86AAAAMElEQVR4nOzNAQkAAAgDMBETvH9YYwiyFdgkqQtdR8RisVgsFovFYrFYLBaLxR/jBQAA///hmYMyAAAABklEQVQDADzNAIkBjBLgAAAAAElFTkSuQmCC">