From 8e199cd975363536c9cafb00b837011dc9587922 Mon Sep 17 00:00:00 2001
From: Paul Irish <paul.irish@gmail.com>
Date: Mon, 19 Mar 2018 10:09:53 -0700
Subject: [PATCH] delay DOM node walking via requestIdleCallback

---
 inject.js | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/inject.js b/inject.js
index 41f9eb5..816f55d 100644
--- a/inject.js
+++ b/inject.js
@@ -285,18 +285,29 @@ chrome.runtime.sendMessage({}, function(response) {
           }
         }
       }
+
+      // Process the DOM nodes lazily
+      function enqueueCheckNodes(node, parent, added) {
+        const checkNodes = _ => checkForVideo(node, parent, added);
+        if ('requestIdleCallback' in window) {
+          requestIdleCallback(checkNodes, {timeout: 1000});
+        } else {
+          checkNodes();
+        }
+      }
+
       var observer = new MutationObserver(function(mutations) {
         mutations.forEach(function(mutation) {
           forEach.call(mutation.addedNodes, function(node) {
             if (typeof node === "function")
               return;
-            checkForVideo(node, node.parentNode || mutation.target, true);
-          })
+            enqueueCheckNodes(node, node.parentNode || mutation.target, true);
+          });
           forEach.call(mutation.removedNodes, function(node) {
             if (typeof node === "function")
               return;
-            checkForVideo(node, node.parentNode || mutation.target, false);
-          })
+            enqueueCheckNodes(node, node.parentNode || mutation.target, false);
+          });
         });
       });
       observer.observe(document, { childList: true, subtree: true });