[layout] Perform replaced aspect-ratio calculation in LayoutUnits.

See bug for more detailed information. Basically the site in the bug had images all with an aspect ratio of 1/1. With browser zoom, we hit a situation where the width != height due to a loss of precision in the conversion from: LayoutUnit -> float -> LayoutUnit. Resulting in a LayoutUnit(1) difference in the width and height. This patch changes the aspect-ratio calculation to all be in LayoutUnits this means we don't have the loss of precision when converting to/from floats. Bug: 1052370 Change-Id: Ic242c224fec17eeec8f1469c0a6c1fe2ed85c4d2
web-platform-tests · Mar 25, 2020 · f72468b · f72468b
1 parent a82dbcb
commit f72468b
Showing 1 changed file with 18 additions and 0 deletions.
diff --git a/css/css-sizing/replaced-fractional-height-from-aspect-ratio.html b/css/css-sizing/replaced-fractional-height-from-aspect-ratio.html
@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1052370" >
+<meta name="assert" content="When determining the size of a replaced element, if it has an aspect ratio of 1/1 then the final height should be exactly equal to its width." />
+<script src="../../resources/check-layout.js"></script>
+<style>
+canvas {
+  float: left;
+  background: green;
+}
+</style>
+<div style="position: relative; width: 254px; zoom: 0.8;">
+  <canvas style="width: 30%;" width="1" height="1"></canvas>
+  <canvas style="width: 30%;" width="708" height="708"></canvas>
+  <canvas id="target" style="width: 60%;" width="2" height="1" data-offset-x="0"></canvas>
+</div>
+<script>
+checkLayout('#target');
+</script>