am a454a7b8: Add method to clear user history dictionary for testing

* commit 'a454a7b85c513fb7b38e70e4e199958e0060c667':
  Add method to clear user history dictionary for testing

java/src/com/android/inputmethod/latin/DictionaryFacilitatorForSuggest.java

@@ -505,6 +505,14 @@ public class DictionaryFacilitatorForSuggest {
         }
     }
 
+    @UsedForTesting
+    public void clearUserHistoryDictionary() {
+        if (mUserHistoryDictionary == null) {
+            return;
+        }
+        mUserHistoryDictionary.clearAndFlushDictionary();
+    }
+
     // This method gets called only when the IME receives a notification to remove the
     // personalization dictionary.
     public void clearPersonalizationDictionary() {