commit 3fa09c2bcfce5ed3887766f56535333a3f83dadb
parent b57e91e6422da2e0dbcd70666d9f3330bb091ae1
Author: Jose Dapena Paz <jdapena@igalia.com>
Date: Wed, 19 Nov 2025 04:57:12 +0000
Bug 2000671 [wpt PR 56064] - ContainerTiming: block upwards propagation for container roots with ignore attribute, a=testonly
Automatic update from web-platform-tests
ContainerTiming: block upwards propagation for container roots with ignore attribute
If an element has containertiming (so it is set as a container timing
root) and containertiming-ignore, it should report the paints in its
tree, but not propagate to container timing root ancestors.
This is practical as it allows to isolate parts of the tree, while still
allowing to record its paints independently. I.e. for an overlay or a
dialog.
Explainer: https://github.com/bloomberg/container-timing/blob/main/README.md
Chromestatus: https://chromestatus.com/feature/5110962817073152
I2P: https://groups.google.com/a/chromium.org/g/blink-dev/c/J-WxY0w7bNk/m/VkqnomK-CAAJ
Ticket for what should happen:
https://github.com/bloomberg/container-timing/issues/26
Bug: 382422286
Change-Id: I6f5aa521cf4fd9e13f7d638fd5b4f8183f6fb823
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7150901
Reviewed-by: Michal Mocny <mmocny@chromium.org>
Commit-Queue: José Dapena Paz <jdapena@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1546663}
--
wpt-commits: 340ed568a16e959546613ef6ed1ea9680d52d279
wpt-pr: 56064
Diffstat:
1 file changed, 52 insertions(+), 0 deletions(-)
diff --git a/testing/web-platform/tests/container-timing/tentative/nested-containertiming-with-ignore.html b/testing/web-platform/tests/container-timing/tentative/nested-containertiming-with-ignore.html
@@ -0,0 +1,52 @@
+<!DOCTYPE HTML>
+<meta charset=utf-8>
+<title>Container Timing: two nested containertiming nodes, with a child img inside of the inner, and a containertiming-ignore in the descendant root</title>
+<body>
+<style>
+body {
+ margin: 0;
+}
+</style>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/container-timing/resources/container-timing-helpers.js"></script>
+<script src="/element-timing/resources/element-timing-helpers.js"></script>
+<script>
+ let beforeRender;
+ async_test(function (t) {
+ assert_implements(window.PerformanceContainerTiming, "PerformanceContainerTiming is not implemented");
+ const observer = new PerformanceObserver(
+ t.step_func_done(function(entryList) {
+ assert_equals(entryList.getEntries().length, 1, 'one entry expected for the image, for the inner containertiming');
+ const entry = entryList.getEntries()[0];
+ checkContainerEntry(entry, 'div2_ct', 'img_id', beforeRender)
+ checkRect(entry, [0, 100, 0, 100])
+ checkContainerSize(entry, 10000);
+ })
+ );
+ observer.observe({entryTypes: ['container']});
+
+ // Add a div that is the container timing root
+ const div1 = document.createElement('div');
+ div1.setAttribute('containertiming', 'div1_ct');
+ document.body.appendChild(div1);
+
+ // Intermediate container timing root with containertiming-ignore blocking
+ // propagation to the parent containertiming root but still receiving paints
+ // from children
+ const div2 = document.createElement('div');
+ div2.setAttribute('containertiming', 'div2_ct');
+ div2.setAttribute('containertiming-ignore', '');
+ div1.appendChild(div2);
+
+ // Add image of width equal to 100 and height equal to 100.
+ img = document.createElement('img');
+ img.src = '/container-timing/resources/square100.png';
+ img.setAttribute('id', 'img_id');
+ div2.appendChild(img);
+
+ beforeRender = performance.now();
+ }, 'A parent containertiming root with transparent nesting policy does not get paints from children containertiming roots with ignore.');
+</script>
+
+</body>
