Bug 1644733 [wpt PR 24087] - [@Property] Serialize property name as a…

…n identifier, a=testonly

Automatic update from web-platform-tests
[@Property] Serialize property name as an identifier

The serialization must follow the "serialize an identifier" algorithm,
otherwise characters like U+0009 CHARACTER TABULATION will not be
escaped correctly.

Bug: 973830
Change-Id: I2dc943a74900adaf147e1615070c152a78cb5767
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2238117
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Anders Hartvoll Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#777302}

--

wpt-commits: f995ed6cb0a58ad94b7169e379966040fca3c18f
wpt-pr: 24087

testing/web-platform/tests/css/css-properties-values-api/at-property-cssom.html

@@ -51,6 +51,8 @@
   @property --initial-value-only {
     initial-value: red;
   }
+  /* U+0009 CHARACTER TABULATION */
+  @property --tab\9 tab {  }
 </style>
 <script>
 
@@ -119,6 +121,7 @@
 test_css_text('--syntax-only', '@property --syntax-only { syntax: "<color> | none"; }');
 test_css_text('--inherits-only', '@property --inherits-only { inherits: true; }');
 test_css_text('--initial-value-only', '@property --initial-value-only { initial-value: red; }');
+test_css_text('--tab\ttab', '@property --tab\\9 tab { }');
 
 // CSSRule.type