prepareForDestruction() was a workaround to fix bug 159372. However since r205786 fixed the root cause, we no longer need the workaround. Just add a RELEASE_ASSERT check to ensure clean state.
Created attachment 289610 [details] Patch
Comment on attachment 289610 [details] Patch r=me if the tests are happy.
Comment on attachment 289610 [details] Patch Attachment 289610 [details] did not pass ios-sim-ews (ios-simulator-wk2): Output: http://webkit-queues.webkit.org/results/2128093 Number of test failures exceeded the failure limit.
Created attachment 289620 [details] Archive of layout-test-results from ews125 for ios-simulator-elcapitan-wk2 The attached test failures were seen while running run-webkit-tests on the ios-sim-ews. Bot: ews125 Port: ios-simulator-elcapitan-wk2 Platform: Mac OS X 10.11.6
Comment on attachment 289610 [details] Patch Attachment 289610 [details] did not pass mac-ews (mac): Output: http://webkit-queues.webkit.org/results/2128166 Number of test failures exceeded the failure limit.
Created attachment 289621 [details] Archive of layout-test-results from ews101 for mac-yosemite The attached test failures were seen while running run-webkit-tests on the mac-ews. Bot: ews101 Port: mac-yosemite Platform: Mac OS X 10.10.5
Comment on attachment 289610 [details] Patch Attachment 289610 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.webkit.org/results/2128173 Number of test failures exceeded the failure limit.
Created attachment 289622 [details] Archive of layout-test-results from ews105 for mac-yosemite-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: ews105 Port: mac-yosemite-wk2 Platform: Mac OS X 10.10.5
Created attachment 289645 [details] Patch
Committed r206299: <http://trac.webkit.org/changeset/206299>