Layout test svg/animations/smil-leak-elements.svg is flaky

[Matt Lewis]

svg/animations/smil-leak-elements.svg is a flaky failure.
The test is flaky on macOS wk1 according to the flakiness dashboard.

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

The first failure happened with this build:
https://build.webkit.org/builders/Apple%20El%20Capitan%20Release%20WK1%20(Tests)/builds/3001

current builds:
https://build.webkit.org/results/Apple%20El%20Capitan%20Debug%20WK1%20(Tests)/r219144%20(2278)/results.html
https://build.webkit.org/builders/Apple%20El%20Capitan%20Debug%20WK1%20(Tests)/builds/2278

[Matt Lewis]

Diff:
--- /Volumes/Data/slave/elcapitan-debug-tests-wk1/build/layout-test-results/svg/animations/smil-leak-elements-expected.txt
+++ /Volumes/Data/slave/elcapitan-debug-tests-wk1/build/layout-test-results/svg/animations/smil-leak-elements-actual.txt
@@ -1 +1 @@
-PASS
+FAIL: -17 extra live node(s)

[Matt Lewis]

Marked test as flaky on macOS WK1:

https://trac.webkit.org/changeset/221736/webkit/

[Ryan Haddad]

The test is flaky on macOS WK2 as well, moved expectation in r278777.

[Fujii Hironori]

Created attachment 460692 [details]
Patch

[Fujii Hironori]

*** This bug has been marked as a duplicate of bug 114280 ***