SimpleTest.requestFlakyTimeout

Interesting: http://mxr.mozilla.org/mozilla-central/source/testing/mochitest/tests/SimpleTest/SimpleTest.js#656

/**
 * Request the framework to allow usage of setTimeout(func, timeout)
 * where |timeout > 0|.  This is required to note that the author of
 * the test is aware of the inherent flakiness in the test caused by
 * that, and asserts that there is no way around using the magic timeout
 * value number for some reason.
 *
 * The reason parameter should be a string representation of the
 * reason why using such flaky timeouts.
 *
 * Use of this function is STRONGLY discouraged.  Think twice before
 * using it.  Such magic timeout values could result in intermittent
 * failures in your test, and are almost never necessary!
 */

That means that the current usage of SimpleTest.requestFlakyTimeout should be removed as much as possible. That sound like an interesting little project to work on, there are currently 586 instances of this function in mxr: http://mxr.mozilla.org/mozilla-central/search?string=SimpleTest.requestFlakyTimeout