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

		if (!this.dnd.canDrop(this.context.draggable.pane, this.pane)) {
			return;
		}

		this.dragOverCounter--;

		if (this.dragOverCounter === 0) {
			this.render();
		}
	}