chore(*): sync scrolls.

Author: MKirova

projects/igniteui-angular/src/lib/grids/grid-base.directive.ts

@@ -7007,7 +7007,7 @@ export abstract class IgxGridBaseDirective extends DisplayDensityBase implements
         this.gridScroll.emit(args);
     }
 
-    private horizontalScrollHandler(event) {
+    protected horizontalScrollHandler(event) {
         const scrollLeft = event.target.scrollLeft;
         this.headerContainer.onHScroll(scrollLeft);
         this._horizontalForOfs.forEach(vfor => vfor.onHScroll(scrollLeft));

projects/igniteui-angular/src/lib/grids/pivot-grid/pivot-grid.component.ts

@@ -1030,6 +1030,14 @@ export class IgxPivotGridComponent extends IgxGridBaseDirective implements OnIni
         return this.values.length > 1;
     }
 
+    protected horizontalScrollHandler(event) {
+        const scrollLeft = event.target.scrollLeft;
+        this.theadRow.headerContainers.forEach(headerForOf => {
+            headerForOf.onHScroll(scrollLeft);
+        });
+        super.horizontalScrollHandler(event);
+    }
+
     /**
      * @hidden
      */

projects/igniteui-angular/src/lib/grids/pivot-grid/pivot-header-row.component.ts

@@ -82,6 +82,10 @@ export class IgxPivotHeaderRowComponent extends IgxGridHeaderRowComponent implem
     public populateColumnDimensionsByLevel() {
         const res = [];
         const columnDimensions = this.grid.columnDimensions;
+        if (columnDimensions.length === 0) {
+            this.columnDimensionsByLevel = res;
+            return;
+        }
         const cols = this.unpinnedColumnCollection;
         let totalDepth = columnDimensions.map(x => PivotUtil.getDimensionDepth(x)).reduce((acc, val) => acc + val) + 1;
         if (this.grid.hasMultipleValues) {