SF can spawn threads (indirectly) during initialization
and we want those to be spawned at URGENT_DISPLAY_PRIORITY
(in theory they should set their own, but some code lives
in vendor libraries and doesn't).
Bug: 10430209
Change-Id: I5b3a8f979297de287614c8eafd8267bef1176e4b
it used to spawn its own thread and return the main thread
to the binder thread pool -- this was confusing the naming
of things in the kernel.
Bug: 10331839
Change-Id: I2d13a6d73409a38109300fcbe6a04b4c41cb5d00
