Add some basic tests for the 'transform-box' property (#7971)
Test for the 'transform-box' 'view-box' value with the viewport being mutated.
diff --git a/css/css-transforms/transform-box/view-box-mutation.html b/css/css-transforms/transform-box/view-box-mutation.html
new file mode 100644
index 0000000..0d4a0ec
--- /dev/null
+++ b/css/css-transforms/transform-box/view-box-mutation.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html class="reftest-wait">
+<title>transform-box: view-box, viewport mutated</title>
+<link rel="match" href="support/greensquare200x200.html">
+<link rel="help" href="https://drafts.csswg.org/css-transforms/#transform-box">
+<style>
+#target {
+ transform-box: view-box;
+ transform: translate(-50%, 0);
+}
+</style>
+<p>There should be a green 200x200 rectangle below, and no red.</p>
+<svg width="400" height="200">
+ <rect width="200" height="200" fill="red"/>
+ <rect id="target" x="100" width="200" height="200" fill="green"/>
+</svg>
+<script>
+requestAnimationFrame(function() {
+ requestAnimationFrame(function() {
+ document.querySelector('svg').setAttribute('width', 200);
+ document.documentElement.classList.remove('reftest-wait');
+ });
+});
+</script>
