src/vs/platform/storage/browser/storageService.ts/BrowserStorageService/migrateOldStorage
class BrowserStorageService:	private async migrateOldStorage(scope: StorageScope): Promise<void> {
		try {
			const stateRoot = joinPath(this.environmentService.userRoamingDataHome, 'state');

			if (scope === StorageScope.GLOBAL) {
				const globalStorageFile = joinPath(stateRoot, 'global.json');
				const globalItemsRaw = await this.fileService.readFile(globalStorageFile);
				const globalItems = new Map<string, string>(JSON.parse(globalItemsRaw.value.toString()));

				for (const [key, value] of globalItems) {
					this.globalStorage?.set(key, value);
				}

				await this.fileService.del(globalStorageFile);
			} else if (scope === StorageScope.WORKSPACE) {
				const workspaceStorageFile = joinPath(stateRoot, `${this.payload.id}.json`);
				const workspaceItemsRaw = await this.fileService.readFile(workspaceStorageFile);
				const workspaceItems = new Map<string, string>(JSON.parse(workspaceItemsRaw.value.toString()));

				for (const [key, value] of workspaceItems) {
					this.workspaceStorage?.set(key, value);
				}

				await this.fileService.del(workspaceStorageFile);
			}
		} catch (error) {
			// ignore
		}
	}