Bug 1052063 - Do a single pass over the APZC tree to advance animations before sampling. r=
Bug 1052063 - Avoid running multiple animation steps if there are multiple layers sharing an APZC. r=
Bug 1052063 - Expand the APZCTreeManagerTester to take care of more boilerplate. r=
Bug 1052063 - Add some tests to ensure layers with the same scrollid get the same APZC. r=
Enable logging
Revert "Enable logging"

This reverts commit 9a3e505526af0800baa9ba356bde55920ecef993.