src/vs/workbench/contrib/markers/browser/markersView.ts/MarkersView/onSelected
class MarkersView:	private onSelected(): void {
		if (this.tree) {
			let selection = this.tree.getSelection();
			if (selection && selection.length > 0) {
				this.lastSelectedRelativeTop = this.tree!.getRelativeTop(selection[0]) || 0;
			}
		}
	}