This patch does the following: 1. Run the same prefixset tests when * browser.safebrowsing.prefixset.max_array_size = 0 * browser.safebrowsing.prefixset.max_array_size = UINT32_MAX This makes sure both of the methods to store prefixset are tested by existing testcases 2. Refine gtest with test fixture 3. Add TinySet and LargeSet testcases Differential Revision: https://phabricator.services.mozilla.com/D30338