Bug 1675130 [wpt PR 26388] - Update wpt metadata, a=testonly

wpt-pr: 26388 wpt-type: metadata
2020-11-06 00:34:14 +00:00 · 2020-11-06 00:34:14 +00:00 · efc6087ee8
--- a/testing/web-platform/meta/css/css-transforms/preserve-3d-flat-grouping-properties-containing-block.tentative.html.ini
+++ b/testing/web-platform/meta/css/css-transforms/preserve-3d-flat-grouping-properties-containing-block.tentative.html.ini
@ -0,0 +1,2 @@
+[preserve-3d-flat-grouping-properties-containing-block.tentative.html]
+  expected: ERROR
--- a/testing/web-platform/meta/css/css-transforms/preserve-3d-flat-grouping-properties.tentative.html.ini
+++ b/testing/web-platform/meta/css/css-transforms/preserve-3d-flat-grouping-properties.tentative.html.ini
@ -1,4 +1,4 @@
-[preserve-3d-flat-grouping-properties.tentative.html]
+[preserve-3d-flat-grouping-properties.html]
  [Preserve-3d element flattened due to backdrop-filter]
    expected: FAIL