Add native tracing API

bug:21195272

Change-Id: I520de9fee7fc40d0570d6bef450d756ce42a1462
diff --git a/native/android/Android.mk b/native/android/Android.mk
index 12fdf71..1742bee 100644
--- a/native/android/Android.mk
+++ b/native/android/Android.mk
@@ -16,6 +16,7 @@
     obb.cpp \
     sensor.cpp \
     storage_manager.cpp \
+    trace.cpp \
 
 LOCAL_SHARED_LIBRARIES := \
     liblog \