浏览器返回时需要重新启动Service Worker（需要刷新）

Question

My service worker is really simple; 我的服务人员非常简单； just a method for caching fonts, JS, and a few other items to accelerate page performance and reduce data transfer. 只是一种用于缓存字体，JS和其他一些项目的方法，以加快页面性能并减少数据传输。

However, when live ( example ) navigating to a second page then using the browser's back button displays the OFFLINE page rather than TRYing first or using the natural browser cache. 但是，当实时（示例）导航到第二页时，然后使用浏览器的后退按钮显示OFFLINE页面，而不是先尝试或使用自然浏览器缓存。

Relevant part of SW: SW的相关部分：

// Clear old caches when activated
self.addEventListener('activate', function(e) {
  e.waitUntil(
    caches.keys().then(function(keyList) {
      return Promise.all(keyList.map(function(key) {
        if (key !== cacheName) {
          console.log('[ServiceWorker] Removing old cache', key);
          return caches.delete(key);
        }
      }));
    })
  );
  return self.clients.claim();
});

self.addEventListener('fetch', function(event) {
  event.respondWith(
    // Try the cache
    caches.match(event.request).then(function(response) {
      // Fall back to network
      return response || fetch(event.request);
    }).catch(function() {
      // If both fail, show a generic fallback:
      return caches.match('/offline.htm');
      // However, in reality you'd have many different
      // fallbacks, depending on URL & headers.
      // Eg, a fallback silhouette image for avatars.
    })
  );
});

This seems more likely (or possibly isolated to) Firefox (current version 59.0.2). 这似乎更可能（或可能仅限于Firefox）（当前版本59.0.2）。