When I ran Web Platform Test /css/css-ui-3/outline-018.html with a debug build of WebKit, the WebProcess crashed because the ASSERT(paused()) failed in AnimationBase::updateStateMachine(). You can run the test online at <http://w3c-test.org/tools/runner/index.html>.
This assert is always hit after entering your password when logging onto a Google account on google.com. /css/css-ui-3/outline-018.html is surely a better testcase, though!
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