[SfStats] Record vsync event connection count

Bug: 135480141
Test: ./statsd_testdrive 10062
Change-Id: I220f0c96935c96afea194ed8ca69922785cf296e
diff --git a/services/surfaceflinger/TimeStats/TimeStats.cpp b/services/surfaceflinger/TimeStats/TimeStats.cpp
index 493a709..8fbce56 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.cpp
+++ b/services/surfaceflinger/TimeStats/TimeStats.cpp
@@ -70,6 +70,7 @@
     mStatsDelegate->statsEventWriteInt64(event, mTimeStats.clientCompositionFrames);
     mStatsDelegate->statsEventWriteInt64(event, mTimeStats.displayOnTime);
     mStatsDelegate->statsEventWriteInt64(event, mTimeStats.presentToPresent.totalTime());
+    mStatsDelegate->statsEventWriteInt32(event, mTimeStats.displayEventConnectionsCount);
     mStatsDelegate->statsEventBuild(event);
     clearGlobalLocked();
 
@@ -269,6 +270,16 @@
     mTimeStats.clientCompositionReusedFrames++;
 }
 
+void TimeStats::recordDisplayEventConnectionCount(int32_t count) {
+    if (!mEnabled.load()) return;
+
+    ATRACE_CALL();
+
+    std::lock_guard<std::mutex> lock(mMutex);
+    mTimeStats.displayEventConnectionsCount =
+            std::max(mTimeStats.displayEventConnectionsCount, count);
+}
+
 static int32_t msBetween(nsecs_t start, nsecs_t end) {
     int64_t delta = std::chrono::duration_cast<std::chrono::milliseconds>(
                             std::chrono::nanoseconds(end - start))
@@ -812,6 +823,7 @@
     mTimeStats.missedFrames = 0;
     mTimeStats.clientCompositionFrames = 0;
     mTimeStats.clientCompositionReusedFrames = 0;
+    mTimeStats.displayEventConnectionsCount = 0;
     mTimeStats.displayOnTime = 0;
     mTimeStats.presentToPresent.hist.clear();
     mTimeStats.frameDuration.hist.clear();