Bug 1027708 - Delay setting the collection datastore listeners until the datastore initial read r=kgrandon
Revert "Bug 1027708 - Disable test_cleanup_gaia for mac r=me"

This reverts commit f8fa13796f95e57e814bf5e72fce73f2aecb67f4.
Merge pull request #21121 from KevinGrandon/AntonioMA-bug1027708_3

Bug 1027708 - Delay setting the collection datastore listeners until the datastore initial read