Move direction and fill tests to subdirectory

third_party/WebKit/LayoutTests/SlowTests

 # This file should only mark tests as Slow. If they are failing in some other way, that listing should be in TestExpectations.
 # Lines listed in both files will have the *union* of the expectations.
 #
 # In general, we should list tests in this file if they are slower than ~30% of the default timeout time, as we
 # can see a 3x variance or more in test times on the bots. In practice, this means that any test that takes longer
 # than 2 seconds in Release mode or 6 seconds in Debug mode should be listed here.
 #
 # Further documentation:
 # https://chromium.googlesource.com/chromium/src/+/master/docs/testing/layout_test_expectations.md
 
@@ skipping 147 matching lines @@
 crbug.com/73609 virtual/mojo-loading/http/tests/media/video-play-stall.html [ Slow ]
 
 # This has been Slow in Debug since added in r164270.
 crbug.com/330389 [ Debug ] css-parser/color3_hsl.html [ Slow ]
 
 # Many of the virtual animations tests are slow.
 crbug.com/248938 [ Linux Win ] virtual/threaded/animations/combo-transform-rotate+scale.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/3d/change-transform-in-end-event.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/3d/state-at-end-event-transform.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/3d/transform-perspective.html [ Slow ]
-crbug.com/248938 virtual/threaded/animations/animation-direction-reverse-fill-mode-hardware.html [ Slow ]
-crbug.com/248938 virtual/threaded/animations/animation-direction-reverse-fill-mode.html [ Slow ]
-crbug.com/248938 virtual/threaded/animations/animation-direction-reverse-hardware.html [ Slow ]
+crbug.com/248938 virtual/threaded/animations/direction-and-fill/animation-direction-reverse-fill-mode-hardware.html [ Slow ]
+crbug.com/248938 virtual/threaded/animations/direction-and-fill/animation-direction-reverse-fill-mode.html [ Slow ]
+crbug.com/248938 virtual/threaded/animations/direction-and-fill/animation-direction-reverse-hardware.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/stability/animation-on-inline-crash.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/cross-fade-background-image.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/cross-fade-border-image-source.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/cross-fade-webkit-mask-box-image.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/cross-fade-webkit-mask-image.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/missing-values-last-keyframe.html [ Slow ]
 crbug.com/248938 virtual/threaded/animations/3d/replace-filling-transform.html [ Slow ]
 crbug.com/311482 virtual/threaded/animations/interpolation/filter-interpolation.html [ Slow ]
 crbug.com/311482 virtual/threaded/animations/prefixed/keyframes-unprefixed-03.html [ Slow ]
 crbug.com/243871 virtual/threaded/fast/scroll-behavior/ [ Slow ]
 crbug.com/243871 virtual/threaded/fast/idle-callback/idle_periods.html [ Slow ]
 crbug.com/664857 virtual/threaded/animations/responsive/transform-responsive-neutral-keyframe.html [ Slow ]
 crbug.com/669911 virtual/threaded/animations/responsive/zoom-responsive-transform-animation.html [ Slow ]
 
-crbug.com/258896 animations/animation-direction-reverse-fill-mode.html [ Slow ]
+crbug.com/258896 animations/direction-and-fill/animation-direction-reverse-fill-mode.html [ Slow ]
 
 # This test has to generate >250MB of data which takes ~6s in both release and debug.
 crbug.com/420240 http/tests/xmlhttprequest/xmlhttprequest-json-response-overflow.html [ Slow ]
 crbug.com/420240 virtual/mojo-loading/http/tests/xmlhttprequest/xmlhttprequest-json-response-overflow.html [ Slow ]
 
 # These html5lib tests are generated tests that test a huge amount of permutations so they need a bit more time.
 crbug.com/453312 html5lib/generated/run-doctype01-data.html [ Slow ]
 crbug.com/453312 html5lib/generated/run-domjs-unsafe-data.html [ Slow ]
 crbug.com/453312 html5lib/generated/run-entities01-data.html [ Slow ]
 crbug.com/453312 html5lib/generated/run-entities02-data.html [ Slow ]
@@ skipping 194 matching lines @@
 crbug.com/676572 [ Debug ] external/wpt/webstorage/storage_local_setitem_quotaexceedederr.html [ Slow ]
 
 # These tests were previously marked Slow in ASANExpectations.
 crbug.com/451577 [ Linux ] inspector/elements/user-properties.html [ Slow ]
 crbug.com/451577 [ Linux ] inspector/layers/layer-canvas-log.html [ Slow ]
 
 # These imported tests exercise tens of thousands of code points and generate large results.
 crbug.com/736056 external/wpt/encoding/legacy-mb-japanese [ Slow ]
 crbug.com/736056 external/wpt/encoding/legacy-mb-korean [ Slow ]
 crbug.com/736056 external/wpt/encoding/legacy-mb-tchinese [ Slow ]