revert viewlines change..

src/vs/editor/browser/viewParts/lines/viewLines.ts

@@ -484,8 +484,7 @@ export class ViewLines extends ViewPart implements IVisibleLinesHost<ViewLine>,
 	 * Returns false if some lines need to be reevaluated (in a slow fashion).
 	 */
 	private _updateLineWidthsFast(): boolean {
-		// TODO@rebornix triggering `updateLineWidthsFast` flushes scroll left.
-		return this._updateLineWidths(false);
+		return this._updateLineWidths(true);
 	}
 
 	private _updateLineWidthsSlow(): void {