SurfaceFlinger: DispSync -> VsyncController

Refactor the old DispSync to separate between Vsync math (VsyncTracker)
and fence / vsync callback management (VsyncController)

Bug: 162888874
Test: examine systraces
Test: SF unit tests

Change-Id: Id275620380a21aeb0017e966910cbf24860cecef
diff --git a/services/surfaceflinger/SurfaceFlingerFactory.h b/services/surfaceflinger/SurfaceFlingerFactory.h
index a0dd999..753476e 100644
--- a/services/surfaceflinger/SurfaceFlingerFactory.h
+++ b/services/surfaceflinger/SurfaceFlingerFactory.h
@@ -34,7 +34,6 @@
 class EffectLayer;
 class ContainerLayer;
 class DisplayDevice;
-class DispSync;
 class GraphicBuffer;
 class HWComposer;
 class IGraphicBufferConsumer;
@@ -56,6 +55,7 @@
 
 namespace scheduler {
 class VsyncConfiguration;
+class VsyncController;
 class RefreshRateConfigs;
 } // namespace scheduler