Fix isIntersecting in Chrome (#3525)

app/javascript/mastodon/components/status.js

@@ -88,9 +88,11 @@ class Status extends ImmutablePureComponent {
   }
 
   handleIntersection = (entry) => {
-    // Edge 15 doesn't support isIntersecting, but we can infer it from intersectionRatio
+    // Edge 15 doesn't support isIntersecting, but we can infer it
     // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/12156111/
-    const isIntersecting = entry.intersectionRatio > 0;
+    // https://github.com/WICG/IntersectionObserver/issues/211
+    const isIntersecting = (typeof entry.isIntersecting === 'boolean') ?
+      entry.isIntersecting : entry.intersectionRect.height > 0;
     this.setState((prevState) => {
       if (prevState.isIntersecting && !isIntersecting) {
         scheduleIdleTask(this.hideIfNotIntersecting);