tests: Vendor blink perf tests (#38654)

Vendors the [blink perf tests](https://chromium.googlesource.com/chromium/src/+/HEAD/third_party/blink/perf_tests/). These perf tests are useful to evaluate the performance of servo. The license that governs the perf tests is included in the folder. Running benchmark cases automatically is left to future work. The update.py script is taken from mozjs and slightly adapted, so we can easily filter (and patch if this should be necessary in the future. Testing: This PR just adds the perf_tests, but does not use or modify them in any way. --------- Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>
2025-09-10 23:18:20 +01:00 · 2025-08-17 11:54:04 +02:00 · 2025-08-17 11:54:04 +02:00 · ee781b71b4
commit ee781b71b4
parent 7621332824
648 changed files with 359694 additions and 0 deletions
--- a/tests/blink_perf_tests/perf_tests/css/ChangeStyleCSSVariableRecalc.html
+++ b/tests/blink_perf_tests/perf_tests/css/ChangeStyleCSSVariableRecalc.html
@ -0,0 +1,98 @@
+<!DOCTYPE html>
+<head>
+    <title>CSS Custom Properties and Variables: Changes that require resolving variable references</title>
+    <script src="../resources/runner.js"></script>
+    <script src="resources/utils.js"></script>
+</head>
+<style>
+    .container > div {
+        display: inline-block;
+        height: 14px;
+        width: 14px;
+        box-sizing: border-box;
+        border: 1px solid green;
+    }
+    .container {
+        height: 0px;
+        overflow: hidden;
+    }
+</style>
+<body>
+    <header id=info>CSS Variables: <button id=button></button></header>
+    <script>
+        const NUM_ELEMENTS = 20000;
+        const PROP_COUNT = 1000;
+        let curBorder = -1;
+        let root = document.createElement('div');
+        root.classList.add(`container`);
+
+        // Add ?ref to URL to run a similar test without CSS Variables.
+        const ref = document.location.href.endsWith('?ref');
+        button.textContent = ref ? 'OFF' : 'ON';
+        button.addEventListener('click', function(){
+            let href = document.location.href;
+            if (ref) {
+                document.location.href = href.substr(0, href.length - 4);
+            } else {
+                document.location.href = href + '?ref';
+            }
+        });
+
+        function hexcolor(i) {
+            let hex = i.toString(16);
+            while (hex.length < 6)
+                hex = '0' + hex;
+            return '#' + hex;
+        }
+
+        function createDOMTree() {
+            for (let n = 0; n < NUM_ELEMENTS; n++) {
+                let div = document.createElement('div');
+                let i = n % PROP_COUNT;
+                div.classList.add(`bg-color${i}`);
+                root.appendChild(div);
+            }
+            document.body.appendChild(root);
+        }
+
+        function createDivRules() {
+            let lines = [];
+            for (let i = 0; i < PROP_COUNT; i++) {
+                lines.push(`.border${i} > div { border-color: ${hexcolor(i)}; }`);
+                if (ref)
+                    lines.push(`.bg-color${i} { background-color: ${hexcolor(i)}; }`);
+                else
+                    lines.push(`.bg-color${i} { background-color: var(--prop-${i}); }`);
+            }
+            return lines.join('\n');
+        }
+
+        // Create a rule which defines 'propCount' custom properties at :root.
+        function createRootRule() {
+            if (ref)
+                return;
+            let lines = [':root {'];
+            for (let i = 0; i < PROP_COUNT; i++) {
+                lines.push(`--prop-${i}: ${hexcolor(i)};`);
+            }
+            lines.push('}');
+            return lines.join('\n');
+        }
+
+        applyCSSRule(createDivRules());
+        applyCSSRule(createRootRule());
+        createDOMTree();
+        PerfTestRunner.measureTime({
+            description: "Measures the performance of the CSS variable reference recalc.",
+            setup: () => {
+                root.classList.remove(`border${curBorder}`);
+                // Using PROP_COUNT to ensure different border values, avoiding the style cache
+                curBorder = (curBorder + 1) % PROP_COUNT;
+            },
+            run: function() {
+                root.classList.add(`border${curBorder}`);
+                forceStyleRecalc(document.body);
+            },
+        });
+    </script>
+</body>