hwui: trace vsyncId for RT animations 

Change-Id: I67d4342daa2ad31f6ac32935fbcee6912c1b1943
Test: manual
diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index 2ef7802..7f472ae 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -891,10 +891,10 @@
 }
 
 void CanvasContext::prepareAndDraw(RenderNode* node) {
-    ATRACE_CALL();
+    int64_t vsyncId = mRenderThread.timeLord().lastVsyncId();
+    ATRACE_FORMAT("%s %" PRId64, __func__, vsyncId);
 
     nsecs_t vsync = mRenderThread.timeLord().computeFrameTimeNanos();
-    int64_t vsyncId = mRenderThread.timeLord().lastVsyncId();
     int64_t frameDeadline = mRenderThread.timeLord().lastFrameDeadline();
     int64_t frameInterval = mRenderThread.timeLord().frameIntervalNanos();
     int64_t frameInfo[UI_THREAD_FRAME_INFO_SIZE];