Strict null check menubarService

src/tsconfig.strictNullChecks.json

@@ -470,6 +470,7 @@
 		"./vs/platform/markers/common/markers.ts",
 		"./vs/platform/menubar/common/menubar.ts",
 		"./vs/platform/menubar/electron-main/menubar.ts",
+		"./vs/platform/menubar/electron-main/menubarService.ts",
 		"./vs/platform/menubar/node/menubarIpc.ts",
 		"./vs/platform/node/minimalTranslations.ts",
 		"./vs/platform/node/package.ts",

src/vs/platform/menubar/electron-main/menubarService.ts

@@ -29,6 +29,6 @@ export class MenubarService implements IMenubarService {
 			this._menubar.updateMenu(menus, windowId);
 		}
 
-		return TPromise.as(null);
+		return TPromise.as(void 0);
 	}
 }
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