SurfaceFlinger: return DisplayStatInfo from getDisplayStatInfo

Code cleanup - return the class instead of passing it as an
output parameter.

Test: SF unit tests
Change-Id: I7a995415a81f3944d93a1cb573c8e3108464bd07
diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index d032b6d..18c899b 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -426,9 +426,10 @@
     thread->setDuration(workDuration, readyDuration);
 }
 
-void Scheduler::getDisplayStatInfo(DisplayStatInfo* stats, nsecs_t now) {
-    stats->vsyncTime = mVsyncSchedule.tracker->nextAnticipatedVSyncTimeFrom(now);
-    stats->vsyncPeriod = mVsyncSchedule.tracker->currentPeriod();
+DisplayStatInfo Scheduler::getDisplayStatInfo(nsecs_t now) {
+    const auto vsyncTime = mVsyncSchedule.tracker->nextAnticipatedVSyncTimeFrom(now);
+    const auto vsyncPeriod = mVsyncSchedule.tracker->currentPeriod();
+    return DisplayStatInfo{.vsyncTime = vsyncTime, .vsyncPeriod = vsyncPeriod};
 }
 
 Scheduler::ConnectionHandle Scheduler::enableVSyncInjection(bool enable) {