Remove virtual/layout_ng_fragment_traversal/ testsuite.

This was somewhat useful during the initial development of
LayoutNGFragmentTraversal, but these days it doesn't serve too much of a
purpose, apart from slowing down the trybots with its ~5000 tests.

The LayoutNGFragmentTraversal feature may potentially affect pretty much
every layout test that we have, so it's hard to pick a suitable subset.
For the record, with LayoutNGFragmentTraversal enabled, the following
tests are failing today [1]:

  external/wpt/css/CSS2/positioning/toogle-abspos-on-relpos-inline-child.html
  external/wpt/css/css-position/position-absolute-in-inline-001.html
  external/wpt/css/css-position/position-absolute-in-inline-002.html
  external/wpt/css/css-position/position-absolute-in-inline-003.html
  external/wpt/css/css-position/position-absolute-in-inline-004.html
  external/wpt/css/css-position/sticky/position-sticky-nested-inline.html
  external/wpt/css/filter-effects/filtered-inline-is-container.html
  paint/invalidation/bugzilla-7235.html

(in addition to a few virtual tests)

The virtual testsuite only covered the one failing test in
external/wpt/css/CSS2/ , and that fact hopefully proves my point (there
are also a unit test or two that fail - also being missed, of course).

[1] https://ci.chromium.org/ui/p/chromium/builders/try/linux-rel/764120/overview

Bug: 1043787
Change-Id: Ifda9dcd26290acdbdd00e7cfcc3a5dc1864a4d5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3071301
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Commit-Queue: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#908808}

third_party/blink/web_tests/FlagExpectations/disable-layout-ng

@@ -649,9 +649,6 @@ crbug.com/591099 virtual/gpu-rasterization/images/favicon-as-image.html [ Failur
 ### virtual/layout_ng_block_frag/
 virtual/layout_ng_block_frag/* [ Skip ]
 
-### virtual/layout_ng_fragment_traversal/
-virtual/layout_ng_fragment_traversal/* [ Skip ]
-
 ### virtual/layout-ng-grid/
 virtual/layout-ng-grid/* [ Skip ]
 

third_party/blink/web_tests/FlagExpectations/highdpi

@@ -27,7 +27,6 @@ virtual/gpu/* [ Skip ]
 virtual/gpu-rasterization/* [ Skip ]
 virtual/layout-ng-grid/* [ Skip ]
 virtual/layout_ng_block_frag/* [ Skip ]
-virtual/layout_ng_fragment_traversal/* [ Skip ]
 virtual/layout_ng_svg_text/* [ Skip ]
 virtual/prefer_compositing_to_lcd_text/* [ Skip ]
 virtual/synchronous_html_parser/* [ Skip ]

third_party/blink/web_tests/FlagExpectations/layout-ng-fragment-item

@@ -8,6 +8,5 @@ crbug.com/1061102 media/picture-in-picture/v2/detached-iframe.html [ Skip ]
 crbug.com/1061102 media/picture-in-picture/v2/request-picture-in-picture-twice.html [ Skip ]
 crbug.com/1061102 media/picture-in-picture/v2/request-picture-in-picture.html [ Skip ]
 crbug.com/829028 virtual/layout_ng_block_frag/* [ Skip ]
-crbug.com/982194 virtual/layout_ng_fragment_traversal/* [ Skip ]
 crbug.com/982194 virtual/webrtc-wpt-plan-b/external/wpt/webrtc/protocol/video-codecs.https.html [ Failure ]
 crbug.com/982194 virtual/webrtc-wpt-plan-b/external/wpt/webrtc/simulcast/h264.https.html [ Failure ]

third_party/blink/web_tests/TestExpectations

@@ -1177,14 +1177,6 @@ crbug.com/829028 virtual/layout_ng_block_frag/fast/multicol/span/outer-column-br
 crbug.com/1079031 virtual/layout_ng_block_frag/fast/multicol/tall-line-in-short-block.html [ Failure ]
 crbug.com/1058792 virtual/layout_ng_block_frag/fast/multicol/vertical-rl/composited-relpos-overlapping-will-change.html [ Failure ]
 
-### With LayoutNGFragmentTraversal (and LayoutNGFragmentItem) enabled:
-
-crbug.com/1225304 virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/positioning/toogle-abspos-on-relpos-inline-child.html [ Failure ]
-
-# Lots of manual tests here; just skip everything - not too interesting for LayoutNGFragmentTraversal anyway:
-virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/cascade/* [ Skip ]
-virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/text/* [ Skip ]
-
 ### With LayoutNGPrinting enabled:
 
 crbug.com/1121942 virtual/layout_ng_printing/printing/fixed-positioned-child-repeats-even-when-html-and-body-are-zero-height.html [ Crash Pass ]
@@ -2825,7 +2817,6 @@ crbug.com/626703 [ Mac ] external/wpt/inert/inert-retargeting-iframe.tentative.h
 crbug.com/626703 [ Mac ] external/wpt/url/url-setters.any.html [ Failure Timeout ]
 crbug.com/626703 [ Mac ] external/wpt/url/url-setters.any.worker.html [ Failure Timeout ]
 crbug.com/626703 [ Mac11.0 ] virtual/scroll-unification-synchronous_html_parser/external/wpt/dom/events/scrolling/scrollend-event-fired-after-snap.html [ Timeout ]
-crbug.com/626703 [ Mac11.0 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-228.xht [ Failure Timeout ]
 crbug.com/626703 [ Linux ] external/wpt/streams/readable-byte-streams/non-transferable-buffers.any.serviceworker.html [ Crash ]
 crbug.com/626703 [ Mac ] external/wpt/streams/readable-byte-streams/non-transferable-buffers.any.serviceworker.html [ Crash ]
 crbug.com/626703 [ Win7 ] external/wpt/streams/readable-byte-streams/non-transferable-buffers.any.serviceworker.html [ Crash ]
@@ -2839,15 +2830,12 @@ crbug.com/626703 [ Win10.1909 ] virtual/prerender/wpt_internal/prerender/session
 crbug.com/626703 [ Mac10.14 ] external/wpt/css/CSS2/backgrounds/background-233.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/streams/readable-byte-streams/general.any.html [ Timeout ]
 crbug.com/626703 external/wpt/css/CSS2/backgrounds/background-intrinsic-004.xht [ Failure ]
-crbug.com/626703 [ Mac10.14 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-284.xht [ Failure Timeout ]
 crbug.com/626703 virtual/layout-ng-grid/external/wpt/css/css-grid/grid-model/grid-areas-overflowing-grid-container-009.html [ Failure ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-001.html [ Failure ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-010.html [ Failure ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-016.html [ Failure ]
 crbug.com/626703 [ Mac11.0 ] external/wpt/websockets/stream/tentative/constructor.any.sharedworker.html?wss [ Timeout ]
-crbug.com/626703 [ Mac11.0 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-088.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/html/cross-origin-opener-policy/iframe-popup-same-origin-to-same-origin.https.html [ Timeout ]
-crbug.com/626703 [ Mac10.14 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-280.xht [ Failure Timeout ]
 crbug.com/626703 [ Mac11.0 ] external/wpt/websockets/stream/tentative/constructor.any.worker.html?wss [ Timeout ]
 crbug.com/626703 external/wpt/css/css-grid/grid-model/grid-areas-overflowing-grid-container-009.html [ Failure ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-002.html [ Failure ]
@@ -2856,19 +2844,13 @@ crbug.com/626703 [ Mac11.0 ] external/wpt/pointerevents/pointerevent_pointercapt
 crbug.com/626703 [ Mac10.14 ] external/wpt/css/CSS2/backgrounds/background-167.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/streams/readable-byte-streams/general.any.worker.html [ Timeout ]
 crbug.com/626703 [ Mac11.0 ] external/wpt/css/CSS2/backgrounds/background-287.xht [ Failure Timeout ]
-crbug.com/626703 [ Mac11.0 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-264.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/html/cross-origin-opener-policy/iframe-popup-same-origin-to-unsafe-none.https.html [ Timeout ]
-crbug.com/626703 [ Mac10.15 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-254.xht [ Crash Failure ]
-crbug.com/626703 [ Mac11.0 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-178.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/css/CSS2/backgrounds/background-intrinsic-006.xht [ Failure ]
-crbug.com/626703 virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-intrinsic-004.xht [ Failure ]
 crbug.com/626703 [ Mac10.14 ] external/wpt/css/CSS2/backgrounds/background-attachment-005.xht [ Failure Timeout ]
-crbug.com/626703 [ Mac11.0 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-057.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-006.html [ Failure ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-007.html [ Failure ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-009.html [ Failure ]
 crbug.com/626703 [ Mac11.0 ] external/wpt/webauthn/createcredential-pubkeycredparams.https.html [ Crash ]
-crbug.com/626703 virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-intrinsic-006.xht [ Failure ]
 crbug.com/626703 [ Mac11.0 ] virtual/restrict-gamepad/external/wpt/gamepad/idlharness-extensions.https.window.html [ Failure Timeout ]
 crbug.com/626703 [ Mac11.0 ] external/wpt/webauthn/getcredential-passing.https.html [ Crash ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-012.html [ Failure ]
@@ -2884,7 +2866,6 @@ crbug.com/626703 [ Win10.20h2 ] external/wpt/streams/readable-byte-streams/non-t
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-008.html [ Failure ]
 crbug.com/626703 external/wpt/streams/readable-byte-streams/general.any.serviceworker.html [ Timeout ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-011.html [ Failure ]
-crbug.com/626703 [ Mac10.15 ] virtual/layout_ng_fragment_traversal/external/wpt/css/CSS2/backgrounds/background-245.xht [ Failure Timeout ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-013.html [ Failure ]
 crbug.com/626703 external/wpt/streams/readable-byte-streams/non-transferable-buffers.any.worker.html [ Crash ]
 crbug.com/626703 external/wpt/css/css-sizing/fit-content-length-percentage-004.html [ Failure ]

third_party/blink/web_tests/VirtualTestSuites

@@ -350,14 +350,6 @@
               "fragmentation"],
     "args": ["--enable-blink-features=LayoutNGBlockFragmentation"]
   },
-  {
-    "prefix": "layout_ng_fragment_traversal",
-    "bases": ["external/wpt/css/CSS2",
-              "external/wpt/css/css-contain",
-              "fast/block",
-              "fast/table"],
-    "args": ["--enable-blink-features=LayoutNGFragmentTraversal"]
-  },
   {
     "prefix": "layout_ng_printing",
     "bases": ["printing"],