src/vs/editor/standalone/browser/standaloneThemeService.ts/StandaloneThemeService/_updateActualTheme
class StandaloneThemeService:	private _updateActualTheme(): void {
		const theme = (
			this._autoDetectHighContrast && window.matchMedia(`(forced-colors: active)`).matches
				? this._knownThemes.get(HC_BLACK_THEME_NAME)!
				: this._desiredTheme
		);
		if (this._theme === theme) {
			// Nothing to do
			return;
		}
		this._theme = theme;
		this._updateThemeOrColorMap();
	}