Add listener callback to keep track of tracing state in SCC

Test: N/A
Change-Id: Iae1fe69b65a449f7e94fecaa17081022b0888c7b
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 5cd9dea..d6a75c3 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -596,6 +596,9 @@
     status_t setFrameTimelineVsync(const sp<IGraphicBufferProducer>& surface,
                                    int64_t frameTimelineVsyncId) override;
 
+    status_t addTransactionTraceListener(
+            const sp<gui::ITransactionTraceListener>& listener) override;
+
     // Implements IBinder::DeathRecipient.
     void binderDied(const wp<IBinder>& who) override;