Bug 1679319 [wpt PR 26648] - [LargestContentfulPaint] Fix invisible image tracking, a=testonly

Automatic update from web-platform-tests [LargestContentfulPaint] Fix invisible image tracking In this CL we change |invisible_images_| to track not just LayoutObject but also the ImageResourceContent, which is in line with how it is tracked in |visible_images_| and is necessary to correctly track background images as well as image source changes that do not impact the LayoutObject used. Bug: 1152846 Change-Id: I2bfa02ef0a6795b7036abecf8f1e342f39e6ea3b Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2561270 Reviewed-by: Steve Kobes <skobes@chromium.org> Commit-Queue: Nicolás Peña Moreno <npm@chromium.org> Cr-Commit-Position: refs/heads/master@{#831333} -- wpt-commits: 35e691574b44ae6ff6251af68e619f5ddebfb07e wpt-pr: 26648
2020-11-26 21:33:01 +00:00 · 2020-11-26 21:33:01 +00:00 · 55980da468
--- a/testing/web-platform/tests/largest-contentful-paint/placeholder-image.html
+++ b/testing/web-platform/tests/largest-contentful-paint/placeholder-image.html
@ -0,0 +1,31 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Largest Contentful Paint: src change triggers new entry.</title>
+<body>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/largest-contentful-paint-helpers.js"></script>
+<img src='/images/green-1x1.png' id='image_id' width="133" height="106"/>
+<script>
+  async_test(function (t) {
+    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
+    let beforeLoad = performance.now();
+    document.getElementById('image_id').src = '/images/blue.png';
+    const url = window.location.origin + '/images/blue.png';
+    const observer = new PerformanceObserver(
+      t.step_func(function(entryList) {
+        let entries = entryList.getEntries().filter(e => e.url === url);
+        if (entries.length === 0)
+          return;
+        assert_equals(entries.length, 1);
+        const entry = entries[0];
+        // blue.png is 133 by 106.
+        const size = 133 * 106;
+        checkImage(entry, url, 'image_id', size, beforeLoad);
+        t.done();
+      })
+    );
+    observer.observe({type: 'largest-contentful-paint', buffered: true});
+  }, 'Largest Contentful Paint: changing src causes a new entry to be dispatched.');
+</script>
+</body>