HTMLMediaElement::resume() may end up calling prepareForLoad() which will end up calling configureMediaControls() which will in turn instantiate the media controls and run JS code, which will trigger RELEASE_ASSERT(!m_activeDOMObjectAdditionForbidden) in ScriptExecutionContext::didCreateActiveDOMObject(). We need to delay the call to prepareForLoad() in resume().
<rdar://problem/42308469>
Created attachment 345312 [details] Patch
Comment on attachment 345312 [details] Patch r=me
Comment on attachment 345312 [details] Patch Clearing flags on attachment: 345312 Committed r233982: <https://trac.webkit.org/changeset/233982>
All reviewed patches have been landed. Closing bug.