tree c35c1a84e5a76d9387db7a58f6397da130ae3518
parent 8287e859da8800f4f775b4678279c7be094ab029
author Ady Abraham <adyabr@google.com> 1596846196 -0700
committer Ady Abraham <adyabr@google.com> 1597282352 -0700

SurfaceFlinger: add a sysprop to ignore present fences

Emulation platform doesn't have accurate present fences.
If VSR is using the the timestamp from these present fences,
then the calculated timeline is jittery and inaccurate.
This change adds a new sysprop,
debug.sf.vsync_reactor_ignore_present_fences, that indicates
VSR to ignore present fences and instead use the vsync callbacks
to calculate the timeline.

Bug: 163165662
Test: Running emulation and collecting systraces
Change-Id: I8785b36d805e08d2cb340e3c15aa2ce4003843db