Cleanup jni 1

Change-Id: Ieb6af8385356e259720b50f1fe46a694a098b30f
diff --git a/native/src/proximity_info.h b/native/src/proximity_info.h
index cdc5a3d..c1eefea 100644
--- a/native/src/proximity_info.h
+++ b/native/src/proximity_info.h
@@ -92,10 +92,10 @@
         // the radius of the key is assigned to zero.
         return mSweetSpotRadii[keyIndex] > 0.0;
     }
-    bool isOnKey(const int keyId, const int x, const int y);
-    int squaredDistanceToEdge(const int keyId, const int x, const int y);
+    bool isOnKey(const int keyId, const int x, const int y) const;
+    int squaredDistanceToEdge(const int keyId, const int x, const int y) const;
     void calculateNearbyKeyCodes(
-            const int x, const int y, const int32_t primaryKey, int *inputCodes);
+            const int x, const int y, const int32_t primaryKey, int *inputCodes) const;
 
     const int MAX_PROXIMITY_CHARS_SIZE;
     const int KEYBOARD_WIDTH;