Looking at the try results again I got "15217 ERROR TEST-UNEXPECTED-FAIL | /tests/content/html/content/test/test_iframe_sandbox_plugins.html | an unexpected uncaught JS exception reported through window.onerror - TypeError: p.startWatchingInstanceCount is not a function at http://mochi.test:8888/tests/content/html/content/test/test_iframe_sandbox_plugins.html:31" on Android opt.
Looking at the try results again I got "15217 ERROR TEST-UNEXPECTED -FAIL | /tests/ content/ html/content/ test/test_ iframe_ sandbox_ plugins. html | an unexpected uncaught JS exception reported through window.onerror - TypeError: p.startWatching InstanceCount is not a function at http:// mochi.test: 8888/tests/ content/ html/content/ test/test_ iframe_ sandbox_ plugins. html:31" on Android opt.