Make computed value of float with absolute positioning be "none".

Even when there's no box, according to spec change
in https://github.com/w3c/csswg-drafts/issues/1436,
computed value of float with absolulte position should be "none".

Bug: 903275
Change-Id: I7df8eb39eb4c5f22cadbfdbe7a96227eb61a09b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1546732Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Commit-Queue: hyunjune kim <hyunjune.kim@samsung.com>
Cr-Commit-Position: refs/heads/master@{#646261}

third_party/blink/renderer/core/css/properties/longhands/float_custom.cc

@@ -15,7 +15,7 @@ const CSSValue* Float::CSSValueFromComputedStyleInternal(
     const LayoutObject*,
     Node* styled_node,
     bool allow_visited_style) const {
-  if (style.Display() != EDisplay::kNone && style.HasOutOfFlowPosition())
+  if (style.HasOutOfFlowPosition())
     return CSSIdentifierValue::Create(CSSValueID::kNone);
   return CSSIdentifierValue::Create(style.Floating());
 }

third_party/blink/web_tests/external/wpt/css/CSS2/floats/computed-float-position-absolute-expected.txt

-This is a testharness.js-based test.
-FAIL The computed value of float with absolute positioning when there is no box should be "none" assert_equals: [display:none] Invalid gCS(test1)['float']; expected "none" but got "left"
-Harness: the test ran to completion.
-