REGRESSION: Multiple svg layout tests have become flaky timeouts

• Component: Animations
• Status: NEW ---

[Ryan Haddad]

Multiple svg layout tests have timed out at least once on macOS bots in the past 2 days:

svg/animations/animations-paused-in-background-page-iframe.html
svg/animations/deferred-insertion.html
svg/animations/change-target-while-animating-SVG-property.html
svg/animations/multiple-animations-ending.html
svg/animations/smil-leak-dynamically-added-element-instances.svg
svg/animations/svglength-additive-from-by-4.html
svg/animations/svgenum-animation-10.html
svg/animations/svg-two-animate-elements-crash.svg
svg/animations/svgenum-animation-3.html
svg/animations/single-values-animation.html
svg/animations/svgangle-animation-grad-to-rad.html
svg/animations/force-use-shadow-tree-recreation-while-animating.html
svg/animations/non-additive-type-by-animation.html

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=svg%2Fanimations%2F

[Ryan Haddad]

Perhaps related, I noticed that svg/zoom/page/zoom-svg-through-object-with-percentage-size.xhtml was reported as missing expected results on this test run, but the test isn't new and does indeed have an iOS expected.txt file:

https://build.webkit.org/results/Apple%20iOS%2011%20Simulator%20Release%20WK2%20(Tests)/r234110%20(6375)/results.html

[Ryan Haddad]

One of the earliest timeouts I see was with svg/animations/end-event-syncbase.svg, which blames https://trac.webkit.org/log/?verbose=on&rev=234078&stop_rev=234077

https://build.webkit.org/builders/Apple%20High%20Sierra%20Release%20WK2%20(Tests)/builds/5757

[Ryan Haddad]

This change was related to animations:
"Remove completed animations from GraphicsLayer, thus avoiding excessive backing store allocation"
https://trac.webkit.org/changeset/234073/webkit

[Simon Fraser (smfr)]

(In reply to Ryan Haddad from comment #3)
> This change was related to animations:
> "Remove completed animations from GraphicsLayer, thus avoiding excessive
> backing store allocation"
> https://trac.webkit.org/changeset/234073/webkit

That shouldn't have any impact on SVG animations.

[Radar WebKit Bug Importer]

<rdar://problem/42643928>

[Truitt Savell]

After further testing and help from Johnathan, I found that running the directories storage/indexeddb/modern/ and svg/ in succession with one test runner reproduced the issue. I bisected the storage/indexeddb/modern/ directory down to find that storage/indexeddb/modern/opendatabase-after-storage-crash.html  is the casue of the flakey timouts. If you run this test in front tof the svg/ directory there is a chance of a timout occuring. 

Test Command Line:
Run-webkit-tests --root testbuild-234505 storage/indexeddb/modern/opendatabase-after-storage-crash.html   svg/ --child-processes 1 -v

I then marked the test as skip locally and ran both directories again 10 times with no timouts occuring. 

Next steps are to mark the test as skip for now and work to find a proper solution.