src/vs/workbench/services/themes/browser/workbenchThemeService.ts/WorkbenchThemeService/applyAndSetFileIconTheme
class WorkbenchThemeService:	private applyAndSetFileIconTheme(iconThemeData: FileIconThemeData, silent = false): void {
		this.currentFileIconTheme = iconThemeData;

		_applyRules(iconThemeData.styleSheetContent!, fileIconThemeRulesClassName);

		if (iconThemeData.id) {
			this.container.classList.add(fileIconsEnabledClass);
		} else {
			this.container.classList.remove(fileIconsEnabledClass);
		}

		this.fileIconThemeWatcher.update(iconThemeData);

		if (iconThemeData.id) {
			this.sendTelemetry(iconThemeData.id, iconThemeData.extensionData, 'fileIcon');
		}

		if (!silent) {
			this.onFileIconThemeChange.fire(this.currentFileIconTheme);
		}
	}