[:is/:where] Add WPT is-specificity-shadow.html

Our specificity calculation for :host() incorrectly uses the maximum specificity for the selector that _matched_ inside :host(). Since no selector matches in this case, the specificity is zero, and we end up applying the wrong thing. Bug: 1143404 Change-Id: Ib3f4d132c36aedeade3fd79d86c960c352eba120 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505896Reviewed-by: Rune Lillesveen <futhark@chromium.org> Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org> Cr-Commit-Position: refs/heads/master@{#822070}

[:is/:where] Add WPT is-specificity-shadow.html
Our specificity calculation for :host() incorrectly uses the maximum specificity for the selector that _matched_ inside :host(). Since no selector matches in this case, the specificity is zero, and we end up applying the wrong thing. Bug: 1143404 Change-Id: Ib3f4d132c36aedeade3fd79d86c960c352eba120 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505896Reviewed-by: Rune Lillesveen <futhark@chromium.org> Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org> Cr-Commit-Position: refs/heads/master@{#822070}
f3573769 · Anders Hartvoll Ruud · Commit Bot · dbdf72f1 · f3573769 · f3573769
Commit f3573769 authored Oct 29, 2020 by Anders Hartvoll Ruud Committed by Commit Bot Oct 29, 2020
2 changed files
--- a/third_party/blink/web_tests/external/wpt/css/selectors/is-specificity-shadow-expected.txt
+++ b/third_party/blink/web_tests/external/wpt/css/selectors/is-specificity-shadow-expected.txt
+This is a testharness.js-based test.
+FAIL Specificity of :host() inside :is() assert_equals: expected "rgb(0, 128, 0)" but got "rgb(255, 0, 0)"
+Harness: the test ran to completion.
+
--- a/third_party/blink/web_tests/external/wpt/css/selectors/is-specificity-shadow.html
+++ b/third_party/blink/web_tests/external/wpt/css/selectors/is-specificity-shadow.html
+<!DOCTYPE html>
+<title>Specificity of :host() inside :is()</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<link rel="help" href="https://drafts.csswg.org/selectors-4/#matches">
+<link rel="help" href="https://drafts.csswg.org/css-scoping/#host-selector">
+<style>
+  main :not(:is(:host(#a))) { color: green; }
+  main :not(:is(:host(.a))) { color: red; }
+</style>
+<main>
+  <div id=element>Green</div>
+</main>
+<script>
+  test(function() {
+    assert_equals(getComputedStyle(element).color, 'rgb(0, 128, 0)');
+  }, 'Specificity of :host() inside :is()');
+</script>