Remove next letters frequency handling

Bug: 3428942
Change-Id: Id62f467ce4e50c60a56d59bf96770e799a4659e2
diff --git a/native/src/unigram_dictionary.h b/native/src/unigram_dictionary.h
index 90c9814..43aafc6 100644
--- a/native/src/unigram_dictionary.h
+++ b/native/src/unigram_dictionary.h
@@ -32,8 +32,7 @@
 public:
     UnigramDictionary(const unsigned char *dict, int typedLetterMultipler, int fullWordMultiplier,
             int maxWordLength, int maxWords, int maxProximityChars, const bool isLatestDictVersion);
-    int getSuggestions(int *codes, int codesSize, unsigned short *outWords, int *frequencies,
-            int *nextLetters, int nextLettersSize);
+    int getSuggestions(int *codes, int codesSize, unsigned short *outWords, int *frequencies);
     ~UnigramDictionary();
 
 private:
@@ -109,6 +108,7 @@
     int mStackInputIndex[MAX_WORD_LENGTH_INTERNAL];
     int mStackDiffs[MAX_WORD_LENGTH_INTERNAL];
     int mStackSiblingPos[MAX_WORD_LENGTH_INTERNAL];
+    int mNextLettersFrequency[NEXT_LETTERS_SIZE];
 };
 
 // ----------------------------------------------------------------------------