src/vs/base/browser/ui/inputbox/inputBox.ts/InputBox/onValueChange
class InputBox:	private onValueChange(): void {
		this._onDidChange.fire(this.value);

		this.validate();
		this.updateMirror();
		this.input.classList.toggle('empty', !this.value);

		if (this.state === 'open' && this.contextViewProvider) {
			this.contextViewProvider.layout();
		}
	}