Fieldset NG: Do not enable LayoutNGBlockFragmentation flag in virtual/layout_ng_fieldset/

We're going to ship LayouNGFieldset before LayoutNGBlockFragmentation.
We should test LayouNGFieldset without LayoutNGBlockFragmentation.

This CL has no behavior changes.

Bug: 875235
Change-Id: Ice80abf0fcdd83ed15fb088b76899287aeb88187
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2331956
Commit-Queue: Koji Ishii <kojii@chromium.org>
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#793527}

third_party/blink/web_tests/TestExpectations

@@ -1217,13 +1217,7 @@ virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/text/* [ Skip ]
 
 # Fieldset in NG
 #
-crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/css/css-contain/contain-size-breaks-001.html [ Crash Failure ]
-crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/css/css-contain/contain-size-monolithic-001.html [ Crash Failure ]
-crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/css/css-contain/contain-size-multicol-001.html [ Failure ]
-crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-size-multicol-002.html [ Crash Failure ]
-crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/contain/contain-size-multicol-003.html [ Failure ]
 crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-flexbox.html [ Pass ]
-crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-multicol.html [ Failure ]
 crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-percentage-block-size.html [ Failure ]
 crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/fieldset-transform-translatez.html [ Failure ]
 crbug.com/875235 virtual/layout_ng_fieldset/external/wpt/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements/legend-align.html [ Failure ]

third_party/blink/web_tests/VirtualTestSuites

@@ -255,7 +255,7 @@
               "external/wpt/css/vendor-imports/mozilla/mozilla-central-reftests/contain",
               "external/wpt/html/rendering/non-replaced-elements/the-fieldset-and-legend-elements",
               "fast/forms/fieldset"],
-    "args": ["--enable-blink-features=LayoutNGFieldset,LayoutNGBlockFragmentation"]
+    "args": ["--enable-blink-features=LayoutNGFieldset"]
   },
   {
     "prefix": "layout-ng-grid",