src/vs/base/browser/ui/splitview/paneview.ts/PaneDraggable/onDragEnd
class PaneDraggable:	private onDragEnd(e: DragEvent): void {
		if (!this.context.draggable) {
			return;
		}

		this.dragOverCounter = 0;
		this.render();
		this.context.draggable = null;
	}