Add missing includes.

Change-Id: Ic7199045d0cffb208871f52cc167194013351d32
diff --git a/native/jni/src/proximity_info.cpp b/native/jni/src/proximity_info.cpp
index c00c4c2..960d401 100644
--- a/native/jni/src/proximity_info.cpp
+++ b/native/jni/src/proximity_info.cpp
@@ -21,6 +21,7 @@
 #define LOG_TAG "LatinIME: proximity_info.cpp"
 
 #include "additional_proximity_chars.h"
+#include "defines.h"
 #include "dictionary.h"
 #include "proximity_info.h"