removed immediate call to deferLazyLoadEnd

lib/lazy/content-lazy-loader.js

@@ -23,6 +23,7 @@
 this.lazyLoader = this.lazyLoader || (() => {
 
 	const LAZY_LOADING_TIMEOUT = 1000;
+	const IDLE_LAZY_LOADING_TIMEOUT = 3000;
 	const MAX_LAZY_LOADING_TIMEOUT = 30000;
 
 	return { process };
@@ -32,27 +33,37 @@ this.lazyLoader = this.lazyLoader || (() => {
 		const scriptBeforeElement = document.createElement("script");
 		scriptBeforeElement.src = scriptURL;
 		document.body.appendChild(scriptBeforeElement);
-		let timeoutId, maxTimeoutId;
+		let timeoutId, maxTimeoutId, idleTimeoutId;
 		const promise = new Promise(resolve => {
+			let srcAttributeChanged;
 			scriptBeforeElement.onload = () => scriptBeforeElement.remove();
-			const observer = new MutationObserver(() => timeoutId = deferLazyLoadEnd(timeoutId, maxTimeoutId, observer, resolve));
+			const observer = new MutationObserver(() => {
+				srcAttributeChanged = true;
+				timeoutId = deferLazyLoadEnd(timeoutId, maxTimeoutId, idleTimeoutId, observer, resolve);
+			});
 			observer.observe(document, { attributeFilter: ["src", "srcset"], subtree: true });
-			timeoutId = deferLazyLoadEnd(timeoutId, maxTimeoutId, observer, resolve);
+			idleTimeoutId = timeout.set(() => {
+				if (!srcAttributeChanged) {
+					timeout.clear(timeoutId);
+					lazyLoadEnd(maxTimeoutId, idleTimeoutId, observer, resolve);
+				}
+			}, IDLE_LAZY_LOADING_TIMEOUT);
 			maxTimeoutId = timeout.set(() => {
 				timeout.clear(timeoutId);
-				lazyLoadEnd(maxTimeoutId, observer, resolve);
+				lazyLoadEnd(maxTimeoutId, idleTimeoutId, observer, resolve);
 			}, MAX_LAZY_LOADING_TIMEOUT);
 		});
 		return promise;
 	}
 
-	function deferLazyLoadEnd(timeoutId, maxTimeoutId, observer, resolve) {
+	function deferLazyLoadEnd(timeoutId, maxTimeoutId, idleTimeoutId, observer, resolve) {
 		timeout.clear(timeoutId);
-		return timeout.set(() => lazyLoadEnd(maxTimeoutId, observer, resolve), LAZY_LOADING_TIMEOUT);
+		return timeout.set(() => lazyLoadEnd(maxTimeoutId, idleTimeoutId, observer, resolve), LAZY_LOADING_TIMEOUT);
 	}
 
-	function lazyLoadEnd(maxTimeoutId, observer, resolve) {
+	function lazyLoadEnd(maxTimeoutId, idleTimeoutId, observer, resolve) {
 		timeout.clear(maxTimeoutId);
+		timeout.clear(idleTimeoutId);
 		timeout.set(resolve, LAZY_LOADING_TIMEOUT);
 		const scriptURL = browser.runtime.getURL("lib/lazy/web-lazy-loader-after.js");
 		const scriptAfterElement = document.createElement("script");