Add viz hit test surface layer metrics

With cc generated hit test data, viz hit test surface layer is capable
of doing synchronous hit testing under some non-trivial cases. Despite
that it still has to do slow path hit testing under some circumstances.
This patch added a metric to record the reasons of slow path hit test.

Bug: 901882
Change-Id: Icaff4c9ba01add4dfc4620b5d7e28fd85683dba9
Reviewed-by: Ria Jiang <>
Reviewed-by: Robert Flack <>
Reviewed-by: Jesse Doherty <>
Reviewed-by: Ken Buchanan <>
Commit-Queue: Xianda Sun <>
Cr-Commit-Position: refs/heads/master@{#607985}
20 files changed