src/vs/platform/theme/common/themeService.ts/Themable/constructor
class Themable:	constructor(
		protected themeService: IThemeService
	) {
		super();

		this.theme = themeService.getColorTheme();

		// Hook up to theme changes
		this._register(this.themeService.onDidColorThemeChange(theme => this.onThemeChange(theme)));
	}