Step 30-A Constize gesture

Change-Id: I6c0b89d96532dc1c8ca71bb730ba22de5592ec67
diff --git a/native/jni/src/dictionary.h b/native/jni/src/dictionary.h
index fd9e770..e9a03ce 100644
--- a/native/jni/src/dictionary.h
+++ b/native/jni/src/dictionary.h
@@ -48,7 +48,7 @@
             int *ycoordinates, int *times, int *pointerIds, int *codes, int codesSize,
             int *prevWordChars, int prevWordLength, int commitPoint, bool isGesture,
             bool useFullEditDistance, unsigned short *outWords,
-            int *frequencies, int *spaceIndices, int *outputTypes);
+            int *frequencies, int *spaceIndices, int *outputTypes) const;
 
     int getBigrams(const int32_t *word, int length, int *codes, int codesSize,
             unsigned short *outWords, int *frequencies, int *outputTypes) const;