[wpt] css=tables/fixed-layout-2 test fix

The test asserted that:

<table style="table-layout:fixed; width:auto">

getComputedStyle().tableLayout == "auto"

This is incorrect per spec:

https://drafts.csswg.org/cssom-1/#resolved-values
table-layout is not defined as "Resolved value"

No existing browsers passed this test.

Change-Id: Icf411e47ed8da1d53e59dea16796dc3a7e48a221
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2580359
Commit-Queue: Aleks Totic <atotic@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Reviewed-by: David Grogan <dgrogan@chromium.org>
Auto-Submit: Aleks Totic <atotic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834938}

third_party/blink/web_tests/external/wpt/css/css-tables/fixed-layout-2-expected.txt

-This is a testharness.js-based test.
-PASS Table-layout:fixed is not applied when width is auto
-FAIL Table-layout:fixed reports it is not applied when width is auto assert_equals: expected "auto" but got "fixed"
-PASS Table-layout:fixed is not applied when width is max-content
-FAIL Table-layout:fixed reports it is not applied when width is max-content assert_equals: expected "auto" but got "fixed"
-PASS Table-layout:fixed is not applied when width is min-content
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/css/css-tables/fixed-layout-2.html

@@ -60,9 +60,9 @@
             100
         ],
         [
-            "Table-layout:fixed reports it is not applied when width is auto",
+            "Table-layout:fixed reports fixed when width is auto",
             getComputedStyle(document.querySelector("x-table:nth-of-type(1)")).tableLayout,
-            'auto'
+            'fixed'
         ],
         [
             "Table-layout:fixed is not applied when width is max-content",
@@ -70,9 +70,9 @@
             100
         ],
         [
-            "Table-layout:fixed reports it is not applied when width is max-content",
+            "Table-layout:fixed reports fixed when width is max-content",
             getComputedStyle(document.querySelector("x-table:nth-of-type(2)")).tableLayout,
-            'auto'
+            'fixed'
         ],
         [
             "Table-layout:fixed is not applied when width is min-content",