Merge from vscode 2a36b7d0d527bf408bae4f96b8386db9d9455113 (#10237)

src/vs/workbench/services/layout/browser/layoutService.ts

@@ -224,4 +224,9 @@ export interface IWorkbenchLayoutService extends ILayoutService {
 	 * Returns the next visible view part in a given direction
 	 */
 	getVisibleNeighborPart(part: Parts, direction: Direction): Parts | undefined;
+
+	/**
+	 * True if a default layout with default editors was applied at startup
+	 */
+	readonly openedDefaultEditors: boolean;
 }