Bug 197425 – [Mac WK2 Debug] Layout Test scrollingcoordinator/scrolling-tree/scrolling-tree-includes-frame.html is a flaky failure

• Component: Tools / Tests
• Status: RESOLVED FIXED

[Shawn Roberts]

The following layout test is flaky on Mojave WK2 Debug

scrollingcoordinator/scrolling-tree/scrolling-tree-includes-frame.html

Probable cause:

Test was added in https://trac.webkit.org/r240505 , then appears to be rebaselined in https://trac.webkit.org/r240536 . 

Test is a flaky failure in all available dashboard history

I cannot reproduce it locally with 500 iterations, and even when running with test list from worker. 

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=scrollingcoordinator%2Fscrolling-tree%2Fscrolling-tree-includes-frame.html

Diff:

--- /Volumes/Data/slave/mojave-debug-tests-wk2/build/layout-test-results/scrollingcoordinator/scrolling-tree/scrolling-tree-includes-frame-expected.txt
+++ /Volumes/Data/slave/mojave-debug-tests-wk2/build/layout-test-results/scrollingcoordinator/scrolling-tree/scrolling-tree-includes-frame-actual.txt
@@ -13,29 +13,6 @@
   (min layout viewport origin (0,0))
   (max layout viewport origin (0,0))
   (behavior for fixed 0)
-  (children 1
-    (Frame hosting node
-      (parent relative scrollable rect at (0,0) size 100x200)
-      (children 1
-        (Frame scrolling node
-          (scrollable area size 85 185)
-          (contents size 308 416)
-          (parent relative scrollable rect at (0,0) size 100x200)
-          (scrollable area parameters 
-            (horizontal scroll elasticity 0)
-            (vertical scroll elasticity 0)
-            (horizontal scrollbar mode 0)
-            (vertical scrollbar mode 0)
-            (has enabled horizontal scrollbar 1)
-            (has enabled vertical scrollbar 1))
-          (layout viewport at (0,0) size 85x185)
-          (min layout viewport origin (0,0))
-          (max layout viewport origin (223,231))
-          (behavior for fixed 0)
-        )
-      )
-    )
-  )
 )

[Radar WebKit Bug Importer]

<rdar://problem/50342107>

[Shawn Roberts]

Updated test expectations in https://trac.webkit.org/changeset/244786/webkit

[Simon Fraser (smfr)]

Created attachment 371095 [details]
Patch

[Simon Fraser (smfr)]

Speculative fix landed in https://trac.webkit.org/r245994