Fix a bug tracking changes to layout shift roots.

Previously, we were setting was_layout_shift_root_ in the constructor for FragmentPaintPropertyTreeBuilder. This didn't work, because the constructor is run twice: in UpdateForSelf and UpdateForChildren, but was_layout_shift_root_ is only read in UpdateForChildren call. Unfortunately was_layout_shift_root_ is incorrectly computed when constructed in UpdateForChildren, because we need to compute it *before* setting Transform and other property tree nodes that can influence IsLayoutShiftRoot. Instead, remove it from the constructor, save it on the context, and only compute it at the beginning of UpdateForSelf. Fixed: 1170878 Change-Id: I2e04cc5f5b61f5e6f5c57099421b698d953cee13 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2660679 Commit-Queue: Chris Harrelson <[email protected]> Reviewed-by: Xianzhu Wang <[email protected]> Cr-Commit-Position: refs/heads/master@{#849159}
valerioadm · Feb 1, 2021 · 3a89363 · 3a89363
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commit 3a89363
Showing 1 changed file with 22 additions and 0 deletions.
diff --git a/layout-instability/transform-above-filter-dynamic.html b/layout-instability/transform-above-filter-dynamic.html
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+<!DOCTYPE html>
+<title>Layout Instability: addition of scale transform above filter</title>
+<link rel="help" href="https://wicg.github.io/layout-instability/" />
+<div id=target style="width: 581px">
+    <div id=moved style="filter: saturate(1.1); width: 300px; height:300px; background: lightblue">
+</div>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="resources/util.js"></script>
+<script>
+promise_test(async () => {
+  const watcher = new ScoreWatcher;
+  // Wait for the initial render to complete.
+  await waitForAnimationFrames(2);
+
+  target.style.transform = "scale(1.1)";
+  await waitForAnimationFrames(1);
+
+  assert_equals(watcher.score, 0);
+}, 'addition of scale transform above filter');
+
+</script>