src/vs/editor/browser/widget/diffReview.ts/DiffReview/_getNextRow
class DiffReview:	private _getNextRow(): HTMLElement {
		const current = this._getCurrentFocusedRow();
		if (!current) {
			return this._getFirstRow();
		}
		if (current.nextElementSibling) {
			return <HTMLElement>current.nextElementSibling;
		}
		return current;
	}