169. LRU - Chrome storage自动清除算法

Chrome在需要的时候会利用LRU算法来清除数据

请观看Youtube 介绍，从6:25开始到7:38。

请实现类似的逻辑LRUStorage。

1. 目的并不是要重现Chrome的内部实现。
2. getData 和setData被调用的时候，需要算作'used'。
3. 由于时间精度问题，class的constructor请支持第二个getTimestamp 参数。

interface OriginData {  origin: string  lastUsed: number  size: number  persistent: boolean}interface LRUStorage {  capacity: number  // to use the data for origin  // return size of the data or undefined if not exist  getData(origin: string): OriginData | undefined    // updating data for origin  // return boolean to indicate success or failure  // If the total size exceeds capacity,  // Least Recently Used non-persistent origin data other than itself should be evicted.  setData(origin: string, size: number): boolean  // manually clear data for origin  clearData(origin: string): void  // change data for origin to be persistent  // it only handles existing data not the data added later  // persistent data cannot be evicted unless manually clear it  makePersistent(origin: string): void }